As one of the most serious meteorological disaster, droughts affect the society, economy and the people's livelihood severely. Since the coming of twenty-first century, there are more frequent droughts in the Southwestern region of China. The serious phenomenon is spreading from Northern China to Southwest China. In order to better understand and comprehend the evolution characteristics of droughts in the Southwestern region of China, the changes of droughts in the different time periods (1961-2013) in the Southwest Yunnan area were systematically analyzed according to the evaluation criteria of Standardized Precipitation Evapotranspiration Index (SPEI) and Standardized Precipitation Index (SPI) as well as the Mann-Kendall (MK) test method and Morlet wavelet analysis. The experimental results indicated that the weather status based on SPI index tended to become remarkably drier than that based on SPEI index in the former 33a in the Southwest Yunnan area. In the following 20a, the contrary is the case. On account of the same evaluation index, the frequency and occurrence time of droughts at the same time period was fundamentally consistent. In terms of the two indices, there were about 3a of periodic changes at four time periods. In the 53a, it tended to become dry based on the evaluation of two indexes in from December to June in the next year and from November to June in the next year. It tends to become slightly dry based on the SPEI index from December to May in the next year and from November to May in the next year while it tended to become slightly wet based on the SPI index. According to the spatiotemporal distribution of dry and wet weather, there were great differences in the spatial distribution of change patterns and change scope in the four time periods that were easy to have droughts based on the evaluation of the two indices, The main reason is that the water balance (precipitation minus evapotranspiration) was increased with the notable increase of the temperature in the researched area. Compared with SPI, SPEI has covered the impact of thermal factors in the potential evapotranspiration, therefore it is more effective to investigate the evolutions of the regional droughts under the background of climate warming.