Abstract: Using the observed hourly precipitation and relative humidity data from the national meteorological stations in Tianjin City,and the forecast data from European Centre for Medium Range Weather Forecasts（ECMWF）,spanning January 2016 to December 2017,we establish a coordinated revised statistical algorithm for precipitation and relative humidity,considering the statistical relationship between them.Results show that the smaller the hourly precipitation is,the greater the dispersion of relative humidity is,together with the obvious diurnal variation characteristics.Furthermore,the greater the accumulated rainfall and the longer the precipitation duration,the more stable the relative humidity.However,due to the fact that in the numerical weather prediction,the distribution of relative humidity always has a large dispersion when there is precipitation.Thus,the result can not be directly offered for operational application and needs to be revised by the collaborative algorithm method.Results show that the adjustment of relative humidity is better for light rain,but lower for moderate rain.