You can apply for the visa for your parents on behalf, but the application form must be filled and signed by themselves.

Mr. Matthew, thank you for your reply.

Do I need my parents original passport ? Or the copy one will do ? Do I need to submit my dad's bank statement?

Do I need to show them my flight tickets?

Ms. Natalia, you do need to present your parents' original passport and your dad's bank statement and the round-way air ticket are also required for the Chian visa application.

Mr. Rich, thanks for your information. Really appreciate that.

Btw, what's the different between single entry and double entry?

Our flight is: K.Lumpur - Shanghai - Beijing - K.Lumpur .

Ms.Natalia, the mainly difference between single entry and double entry lies in how many times you can enter Chian with the visa within its valisity.
You can enter China once with the single entry visa and enter China twice with the double entry visa.
A single entry visa is enough for you according to your travel schedule.