Based on the daily precipitation data of 24 precipitation stations and the runoff and sediment data of Taiping station in Mengjiang river basin from 1960 to 2020，its seasonal and interannual variations of precipitation，runoff and sediment were analyzed.Its trend components were analyzed by using linear trend regression test，its mutation was analyzed by using Mann-Whitney-Pettitt mutation point analysis，and its periodic components were analyzed by Morlet wavelet analysis.The results showed that summer precipitation，runoff，sediment load and winter precipitation showed no obvious decreasing trend，the rest of the series showed no obvious increasing trend.Annual precipitation，annual runoff and annual sediment load showed no significant increasing trend，no significant mutation；the annual precipitation series showed the cycles around 4 years，7 years，20 years and 45 years；the annual runoff series showed the cycles around 3 years，7 years，19 years，50 years；the annual sediment load series showed the cycles around 4 years，6 years，11 years，16 years and 46 years.Human activities dominated the reasons for the decrease of annual sediment discharge in the Mengjiang river basin.