Tropical forest in Hainan Island is one of the typical tropical forest ecosystems in China. Its long term climatic dynamics is important for global change research. Climatic factors were analyzed with the meteorological data recorded in the Jianfengling (JFL) National Key Field Research Station for Tropical Forest Ecosystem from 1957 to 2006. The characteristics of abrupt and abnormal climate change and its cycle in JFL tropical forest were analyzed by the accumulative anomaly method, Mann-Kendall test and wavelet analysis. The results demonstrate that annual mean air/ground temperature, and annual mean minimum air temperature increased in recent 50 years, and presented an abrupt change in 1978. Annual mean maximum air temperature, annual mean relative humidity and mean vapor had abrupt changes from low period to high period near 1988. The evaporation changed from high to low, and the abrupt change occurred in the time of 1988-1990. Air and ground temperature were abnormally high when the strong intensity ENSO event happened in 1998. All of these mentioned above indicate that the climatic change of forest is just the obvious response to the global abnormal climate change. Climate change presents a 10 to 25 years cycle in JFL forest indicated by the Morlet Wavelet analysis method.