Trends analysis method, wavelet analysis, Mann-Kendall abrupt change test and temporal GIS were used to analyze the spatial distribution characteristics and temporal trends of precipitation based on the annual precipitation observed data from 1952 to 2012 in Sanjiang Plain. The analysis results showed that there was no obvious change trend during the whole time span with several internal variation trends for annual precipitation in five administrative areas, which meant that it existed four main periods of 28, 22, 15 and 6 years for annual precipitation series. For the whole series of precipitation in the Sanjiang Plain, there were no obvious change trends with the following internal variation trends, that was, there was a downward trend from 1955 to 1979, after then an upward trend until 1997, and then there was a downward trend in the remained annual precipitation series. There was an obvious spacial variation for precipitation. It showed that the precipitation in the middle of Sanjiang Plain was more than that in the two sides where from the north to the south during 1952 to 1954, while there was less precipitation in the middle than that in both sides where from the north to the south during 1955 to 1978, and then there was a trend of more precipitation in the north and east, and less precipitation in the south and west in Sanjiang Plain during 1979 to 2012. In addition, for both the whole Sanjiang Plain and each administrative area, the annual average precipitation amounts during 1952—1954 and 1997—2012 were more than that during 1955—1996.