Usual radiosonde data (1988 to 1997,07:00,19:00) and surface precipitation data (1988 to 1997) are used, and the natural precipitation efficiency in summer in Jiangxi is calculated and analyzed. The results indicate that the average precipitation efficiency in summer is 7.65% in the period of 1988 to 1997, 7.04%, 9.90%, 6.02% in July, August, September in Jiangxi Province, respectively. The maximum precipitation efficiency is 13.77%. The minimum precipitation efficiency is 3.55%. Under the influence of the weather of low-pressure convergent systems, the precipitation efficiency is the greatest (20.48%) and under the influence of the weather of typhoon low systems, the precipitation efficiency is the least (3.33%). The precipitation efficiencies are 11.90%, 8.56%, 7.05%, 7.04% under the weather systems of low-though, typhoon low pressure, continental high pressure, easterly wave, respectively.