A statistical analysis on the intensity change of tropical cyclones (TC) that pa ssed Taiwan is performed. The data of 58 years (1949-2006) from Typhoon yearbook and tropical cyclone yearbook compiled by Chinese Meteorological Administration (CMA) is used. The records of each typhoon are linearly interpolated to one hou r per record. Only TCs that passed Taiwan are picked out for analysis. Several c onclusions can be obtained from the statistics. First of all, the intensity loss of TCs landing from the east side is twice more than that of TCs from west side . Secondly, the more perpendicular the angle between the route direction of land ing TC and long axis of Taiwan central mountain, the smaller the intensity loss and duration on the land. Thirdly, there is a positive correlation between the i ntensity loss and initial intensity for the TCs landing from the east side where as no such correlation exists for TCs from west side. Fourthly, the probability that the intensity remains the same or increases of TCs landing from the west si de is higher than that of TCs from the east.