Abstract. As a very efficient tool, π calculus could do modeling and make evaluations effectively particularly by targeting the features of concurrency and mobility which quite commonly exist in the software system nowadays. After a brief introduction of π comparison, this paper mainly discusses a comparison algorithm based on π comparison which is frequently used in the software modeling. As the ways of data storage mainly concern about random storage of elements and linked list storage of elements, this paper analyzes the algorithm of comparing any two elements in both ways. Particularly, the efficiency analysis is carried on to the element comparing algorithm in the linked list storage, which is relatively complicated, finding that the designed algorithm in this paper is greatly improved not only in algorithm simplification but also in working efficiency.