Abstract: To control casing corrosions caused by interlayer water and expand oil well life, and solve the technical problems of easy lost circulation and long isolation section, a new cementing system needs to be developed. Based on the analyzing of physical characteristics and chemical compositions of the swelling perlite, and a lot of laboratory tests, a lightweight perlite cement slurry system was developed. Field applications showed its stable performances, high compression strength, low cost and wide application prospect.