Using the monthly global land and ocean precipitation reconstruction data set during 1948—2003,the trend variation of tropical annual precipitation fields and the relationship between the tropical annual precipitation and ENSO events have been investigated.Evidence suggests that a negative trend dominated the annual precipitation field.Thirteen regions with significant trend of precipitation are detected.Results show that the precipitation regions with a significant trend over the sea are wider than those over the land areas,and the positive trend regions mostly lie over the Southern Hemispheric Oceans,and the significant precipitation trends over the Northern Hemispheric Oceans are all negative.It is also shown that the ENSO events may serve as one of the significant causes for precipitation reduction in the tropics.Meanwhile,the drought and flood areas in ENSO event years are also identified and compared with the researches available.