Abstract:Based on the monthly mean SST data of Hadley Center of sea ice and SST in 1980-2014, best-track data from the United States Joint Typhoon Warning Center (JTWC) and NCEP/NCAR reanalysis monthly mean data, by using the generalized equilibrium feedback assessment (GEFA) obtained the response factor and response amplitude of South Indian Ocean tropical cyclone frequency to significant basin. The main conclusions are as follows:(1) The frequency of tropical cyclone in southern Indian Ocean has a significant response to NP1 and TA2, respectively, through the 99% and 96% Monte-Carlo test, corresponding response amplitudes were 0.67 and 0.49.(2) The GEFA response results of the local environmental factors on the critical SSTA model are shown:when NP1 appears similar to the positive phase of Pacific Decadal Oscillation(PDO), 850 hPa relative vorticity at 15°S near India Ocean has a significant positive response from the west to the east zone, vertical wind shear showed significant negative response in most of the sea area in the east of Madagascar, 600 hPa relative humidity showed a significant positive response in some sea areas in the east of Madagascar; when TA2 corresponds to a positive time anomaly, 850 hPa relative vorticity and 600 hPa relative humidity showed a significant positive response in the Australia's Northwest Indian Ocean, vertical wind shear is a significant negative response in Australia's Northwest Indian Ocean area.