In this work, 119Sn is used as probe-atom, nd room temperature Mossbauer measurement of Bi1.68Pb0.32Sr1.75Ca1.75Cu2.65-xSnxOy(x=0.2-0.8) sample is performed. Combined with the results of X-ray diffraction and electric characteristic measurement, the relation between the occupancy of Sn in the sample and its electric characteristics is analysed, and an conclusion that squarecoordinated Cu performs a chief influence on the electric characteristic of high-transition-temperature (Tc) phase superconductor is reached.