On China domestic flights, usually each first-class passenger is entitled to have two pieces of carry-on luggage; each business-class and economy-class passenger is entitled to have one piece of carry-on luggage; the size of each carry-on luggage should be smaller than 20 X 40 X 55 centimeter (7.8 X 15.7 X 21.6 inches) and total weight should be less than 5 kg (11 pounds). Thus, your guitar should be checked with other luggage.