China has its own travelocity, Expedia and Orbit (I think one or all of them has a stake in the sites below) - good fare search websites in English:

Ctrip www.ctrip.com
Elong www.eling.com
Yoee www.yoee.com

Domestic fares have a "face value", i.e. full Y fare. Airlines sell discounted fares from 20% of Y onwards. Unlike the US where last-minute fares are usually prohibitively expensive, last minute fares are reasonable (i.e. full Y) or even less than "earlybirds".