Abstract: In order to explore follow-up heavy oil development methods,steam stimulation pilot testing of oil-layers in Qi 40 block was carried out in 1998. During the past 10 years,the pilot testing has undergone three stages: hot inter-well communication,steam stimulation and steam breakthrough. The recovery from steam stimulation is 26. 2% and the ulti-mate recovery is 62.8%,achieving better development effect. According to production-injection ratio and the vari-ance characteristics of temperature,pressure and residue oil saturation,the steam stimulation evaluation has been carried out. Besides that,the technical indicators such as tempera-ture,pressure and steam chamber has been analyzed,which provides reference for dynamic adjustment of steam stimula-tion in Qi 40 block.