Nowadays, there is no unified cognition of relative amplitude-preservation processing, which nevertheless is the basis of reservoir lithologic exploration. Systematic analysis of key processing technique is poor too. Based on years of experience obtained in real data processing and an analysis of the difficulties existent, the author put forward several criteria and then further analyzed such key techniques as amplitude processing, noise attenuation and resolution improvement to obtain the pros and cons in amplitude-preservation. The results may have certain referential significance in further data processing.