Object-Oriented program slicing technique is widely used in program analysis, program comprehension, software testing, and software maintenance etc. In this paper, the basic concepts of abstract data slice and intra-class slice are created at first. Then, the cohesion existing in JAVA language is discussed based on these slices. Finally, the data cohesion, method cohesion and class cohesion are presented and solved by analyzing the relationship between these slice and data, method or class.