The development level of modern service industry is an important symbol of synthetically competence and modernization. The paper analyses the difference of modern service industry in gross and structure between regions in Jiangsu province based on the data of 13 cities, sets up set of assessment index system of modern service industry of Jiangsu province, establishes the evaluation model through Factor Analysis using SPSS (Statistical Product and Service Solutions), calculates respective marks on modern service industry by different cities. Based on the economical analysis on the marks, proposes measures to promote the modern service industry.