In terms of visiting a developing country, the culture shock you will experience in China is probably more subtle than that of other countries like India or some countries in Africa. The rapid development of the economy in the larger cities and the fact that most tourists will likely not venture too far out into the hinterlands means that on the surface, things appear very developed and in some ways, more cosmopolitan than your hometown. You will probably not see a lot of abject poverty (it’s here but you probably won’t come across it) or shocking human sights.
That said, it's China. Things are very different here than what you're used to at home. It's a good idea to have a level of understanding of what you might come up against.
The Culture Shock
So the culture shock a typical tourist enjoys in China is just that – coming face-to-face with a wholly different culture and dealing with those aspects.
Aircraft Arrival - the Seat Belt Sign Is Still On!
Folks in these parts are pretty anxious to get off the airplane, especially after a long flight. When you land on a China-bound flight, you’ll find people jumping up to get luggage before the plane has even landed. If you’re in an aisle seat, the person next to you may ask you to get up so he/she can get his/her luggage before touchdown. Politely point at the lit seatbelt sign or simply ignore the person until touchdown. Getting off the plane can be a free-for-all so just take it slow and don't take the pushing personally.
Taxi lines are thankfully pretty civilized these days. There will be a queue with a person in charge of directing traffic and passengers. You shouldn’t find people pushing and shoving but you might have people smoking furiously all around you.
Walking - Look Both Ways, a Lot
Keep this in mind and you’ll be OK: legs are the lowest form of transportation. Despite the observances from your own culture, a pedestrian is expected to yield to everyone else. Buses will not stop for you. Even when you are crossing the street on a walk sign and you have the right-of-way, and you are holding the hand of an octogenarian while pushing a stroller with twin infants, yield to bicycles and cars because they will not stop for you. Keep keen when crossing the street.
Note that jaywalking is probably not legal but everyone does it all the time.
Personal Space - Elbows Out
You will be pushed and shoved. It is nothing personal. There doesn't seem to be the same reverence for personal space in China as there is in other places. Don’t expect a "sorry" or "excuse me" either. In crowded areas like lines for transportation (e.g. trains), on the subway or going into an elevator, just stand your ground and guard yourself.
Note: there is no such thing as an overcrowded elevator. You might be at the back thinking there is no way another person could possibly squeeze on but you’d be wrong.
Lines or Queues - Mostly Ignored
You will be cut off at some point in your trip. Mostly it happens because you're observing number 5 (see above). The problem is, a gap that big (e.g. you can slip a piece of paper between your face and the preceding person's back) will be perceived as the end of the line, just asking someone to slip in. Either get comfortable with confrontation or don't be in a hurry.
Everyone Is Yelling
Folks here talk at a louder level than you may be used to, especially when they're excited (and this is coming from a person who tends to think she needs to talk louder while on the telephone). Especially on mobile phones, you’ll find people shout away. They're not the least bit angry.
Beware: there is a direct correlation between the length of time you spend in China and the decibel level of your voice on a mobile phone.
First Refusal - Try, Try Again
A lot of times we visitors put our hosts in awkward situations that we think are not awkward at all. Asking for something that isn't on the menu is one example. Quite often a request that you'll think is really something simple will throw the receiver of that request for a loop and the initial response will either be "I don’t know," or an outright "No."
Don't get angry or give up. Just keep a smile on your face and keep asking. Assuming it isn't anything ridiculous, e.g. why can't I park my motorcycle on this table?, eventually they will probably come around.
The Chinese government has held a number of public education campaigns associated with things like the Olympics and the 2010 Expo that have been meant to remind folks not to spit. It still happens but not quite as much as it used to. Government educators aside, in some demographics, it is perfectly acceptable to hawk and spit while walking down the street. This can be uncomfortable when the result of this expectoration ends up beside your newly pedicured toenails.
Throwing Garbage on the Street
The whole "litterbug" educational campaign has not swept China. Folks tend to toss things aside (even from several flights up) and into the street. Part of this tendency might be due to the fact that they're used to someone cleaning up after them (see next list point).
You will never see cleaner streets and sidewalks. Chinese cities employ thousands of people whose job it is to sweep the sidewalks and streets of cigarette butts, litter, leaves, etc. It's a thankless, never-ending job but the streets are very tidy.
Friendly With Kids
If you travel to China with kids, especially young blonde ones, you will probably be overwhelmed at the attention they get. It is all meant very kindly. It can be intrusive and you might even find it rude, but it is meant in the best way. Folks will never tire of trying to get your baby to smile, teasing your toddler and fondling cheeks. Complete strangers will comment on every aspect of your child-rearing and you will find out that you have either overdressed or under-dressed your kids, aren't feeding them the right food or feeding them very well indeed.