Abstract: In this paper, we divided the Jiangsu area (30.5°N ~35.5°N, 116°E ~122°E) into 18 sections in which each section has the range of 1°×1°. We collected the phase data of Jiangsu Digital Seismic Network from January 1, 2009 to December 31, 2017. Using the multi-station methods, we calculated the velocity ratio and possion's ratio of the 18 sections. The results show that: ① In 18 sections, the mean velocity ratio ranges from 1.68 to 1.73, the correlation coefficients are above 0.99, the average velocity ratio value of the whole are is 1.71, which is lower than the average value of the global continental crust. ② The average poisson's ratio value is 0.24. This shows that there is no melting medium property in the study area, consistent with the crust medium which mainly consist of granite. ③ From the relevance of poisson's ratio and crust thickness, there is a negative correlation between the poisson's ratio and crust thickness in Jiangsu area, which is higher in the north and lower in the south, higher in the east and lower in the east. The Poisson's ratio of some sub-regions near 33°N, alternates high and low and changes complicatedly, which may be related to complex geological structure in the study area.

Key words: Jiangsu area, the Multi-station methods, Velocity ratio, Possion&apos, s ratio, Crust thickness