In this paper, part features are classified and then its coding system is constructed by the considered characteristics of features in assemble process. Analyzing the characteristics of features, code values about part features are determined. Assembly process is divided into five functions such as transporting, handing, approaching, alignment and joining, and then the detail parameters of each functions such as determined. Code values about assembly process are determined according to detail parameters. The detail parameters are kinds of available working method and assembly tools when each assembly function is going on. By the coding system, available assembly process can be grasped and perceived for the part that it is difficult to assemble.