Abstract: Study on the residual oil distribution regularity is often of importance and difficulty during the middle and late period of oil field production. According to the production patterns in the M-1 area of Maling Oil Field, we make use of the technology of integrated 3-D geological modeling with reservoir numerical simulation. After the study of trap, fine layer comparison, deposition facies and flowing unit, a 3-D geological model for the M-1 area is established from Yanchang formation to Fuxian formation, which supplies an original geological model for the reservoir numerical simulation. Based on a successful history regression, the residual oil distribution is calculated with reservoir simulation. Finally, we analyze the residual oil distribution regularity combining with study of deposition facies and flowing units. As a result, the potential of the oil field and the adjusting direction for next production is determined.