The coherency/variance cube technique has been developed in recent years as a new technique of seismic data interpretation.In this paper,C3 coherency and variance cube algorithms are emphatically discussed.The authors have designed a software for processing seismic data in the coherency/variance cube technique.Using time slice and leveled layer slice,we can explore small faults and analyze geological structures through investigating the similarity of seismic signals between adjacent traces on the seismic cube.An analysis and interpretation of practical data show that the coherency/variance cube technique is very effective in fault interpretation in that it can improve the interpretation precision and shorten the exploration period.