Abstarct: Reflection seismic is one of the most commonly used geophysical method for oil and gas exploration. The CMP stack method usually employ for seismic imaging. Conventional seismic imaging method baxsed on the CMP stacking does not use the full potential of the dataset due to reflection point dispersal in the presence of dipping reflectors or laterally inhomogeneous media. Application of the CRS stack technique is advantageous in complex areas, since it involves information about the shape of seismic reflectors, i.e., dip and curvature, into processing. Moreover, a multiparameter formula allows to sum up more traces during the stack. Each on of together, this leads to better imaging results, especially to an improvement of the signal-to-noise (S/N) ratio. Reflection events in the CRS stack sections appear clearer and more continuous compared to conventional CMP stack sections. But the CRS stack method encounter in situations where exist conflicting dips at one sample in ZO section, not efficient to deliver consistent high quality images in such cases. The reason for this problem is the search strategy for CRS attributes ( ). In this strategy at the conflicting dips situations,only one reflection event selected that strongest event at that sample with respect to the higher coherency along the CRS operator. The coherency analyses along various test stacking operators are performed for each particular ZO sample to be simulated. Common diffraction surface (CDS) stack method recently introduced for solving the conflicting dips problem. This method by means of DMO idea within CRS strategy resolved this problem. In this case, the number of conflicting dips in each sample is not worried. Therefore any reflection or diffraction event will contribute to the stack for a same sample. For each sample, a coherency analysis is done in a range of angles. Solving the problem of conflicting dips will enhance the usually weak diffraction events in the stacked section. Consequently, noises and other unwanted events disclose similar reflection or diffraction events and make dirty ZO section. In this thesis, we introduce a new method namely Finite-Offset CDS stack. A new offset on the common-diffraction-surface (CDS) stack method was developed to enhance the quality of the structures that have problem of conflicting dips. For this purpose, the new idea applied on CDS travel time formula in defined offset range for each time and target zone to compute finite offset stacked CDS volume. For defining the offset range that used in CDS Operator, for each , a linear function designed that varies with time.Results of using new operator on the synthetic and realseismic data examples display the good performance of the FO-CDS stack method in comparison with other stack methods.