Abstract: Taizhou Formation Reservoir of Caoshe Oilfield is a small complex fault block reservoir. It started waterflood development in 1990,and adopted the recovery method of "waterflooding in river channel,oil producing in point bar". Since then,the yearly production stably went up,and was more than 2×10⁴t in 6 successive years. Its oil production rate reaches 2%,and its waterflooding control level and its recoverable reserves are improved. The research shows that the key to develop the small complex fault block reservoir is to choose the reasonable flood pattern and to take the matching measures,such as oil producing wells transferred to water injection well,oil pumping in depth,perforations adding, formation adjusting,and so on. In that case,better developing results could be obtained.