In this essay, it is attempt to classify the climate in Taiwan into several seasons reasonably. Among all the climatic elements which affect the human body, the wet bulb temperature is the most important one. The sensible temperature varies very much and hard to measure by any instrument. But, there is a high correlation between the sensible temperature and wet bulb temperature. Taking all these factors into consideration. the wet bulb temperature is the most suitable elements to descrive the human sensation and to classify the seasons of climate. From the point of view of the wet bulb temperature, it is sugested that the Taiwan's climate could be devided into six seasons, such as winter, spring. pre-summer, mid-summer, post-summer and autumn.