Abstarct: Lali anticline is one of the oil fields located in Khuzestan province, 60 km northeast of Shushtar. In terms of regional divisions, the Lali oil field is located in the north of Dezful embayment, between Zeilai and Karun oil fields. Its trend follows the trend of Zagros folds and is along the northwest-southeast. In this research, using available data, surface and subsurface structural analysis of Lali anticline has been performed. As the geometric properties of Asmari and Bangestan formation top in Lali oil field have been studied using Asmari and Bangestan Underground contours (UGC) map. Then it has been analyzed using satellite images to identify surface fractures. The highest density of surface fractures is in the area of the southwest flank. For the subsurface fractures study we applied the mathematical derivation methods, circle derivative analysis method and frequency relative fractures (RFF) method. baxsed on these methods, it shows that the first derivative maps of the top of Asmari reservoir, the highest dip of the limbs in this reservoir is related to the thrust faults in the southwest limbs. In the first derivative map, the top of Bangestan reservoir has the highest dip of the limbs in connection with the southwestern area and the northeastern limb. According to the second derivative map, the highest rate of slope changes and therefore the tendency to develop fractures due to transverse curvature of the structure, in the Asmari horizon is related to the southwest limb and in Bangestan horizon is related to the middle and southern area of the southwest limb. The studies performed using the circular derivative method show that all seven zones of Asmari reservoir in Lali oil field are disposed to fracture and the first and second zones of this reservoir have a tendency to develop more fractures than deeper zones. Accordingly, the areas of deep and dense fractures in the central and southeastern part of the reservoir, which has a higher transverse curvature than its western area, are more and due to the higher dip of the southwest limb, the development of fractures, especially on the Bangestan horizon. It is inclined to the southwestern area. Considering to the RFF method, the maximum fracture density in this method is related to areas with shallower depth in the outer arc of the anticline axis. The results obtained in this study can be generalized to other reservoirs with Asmari and Bangestan horizons and can be used to analyze and investigate reservoir fractures.