The regulations of free luggage allowance are varied according to the different airlines. You should check with your carrier on time to get the latest and the accurate information. In China for the domestic airline the stipulations about the check-on and carry-on luggage at moment are as follows:
1. 40kilograms (88 lbs.) for first-class passenger

2. 30 kilograms (66 lbs.) for business-class passenger.

3. 20 kilograms (44 lbs.) for economy-class passenger

4. no free baggage allowance is granted to infants paying ten percent of the adult fare.
If your luggage is overweight, the excess amount will incur an additional charge reckoned by distance and weight: Generally, 1 kilogram (2.2 pounds) costs 1.5% of a full economy-class airfare (one way, adult ticket).
For the carry-on luggage:
The first-class passengers who hold adult or child tickets are permitted to carry on two pieces of hand baggage. For business or economy class passengers, only one piece of carry-on luggage is allowed. Your hand baggage should be less than 5kilograms (about 11 pounds) in total and any piece must have dimensions no larger than 20×40×55cm (8×16×22 inches). Any items that exceed these criteria are treated as checked luggage.
In China each passenger is allowed to take on board not more than one liter (excluding alcohol). Each container should contain no more than 100 ml. The liquid container should be carried in a transparent plastic bag for the convenience of security checking. Duty-free liquid brought from other countries should also be packaged and checked in this way. Alcohol can only be taken as checked luggage. Liquid medicine and milk within a certain limit are allowed subject to checking.
Currency, securities, jewelry, important files, breakable items and other valuables are not allowed to be included as check-on baggage. Any of the items mentioned will be taken as common baggage in case of any compensation claims for damage.
Dangerous articles, such as inflammable, explosive, corrosive, poisonous, radioactive, polymerizing or magnetized material; firearms, sharp or lethal weapons and any articles forbidden or limited to import or export according to Chinese laws are prohibited to be shipped.