The effect of two rocket precipitation enhancement cases for convective cloud in Jiangxi Province is evaluated using the methods of historical regression analysis and timeseries comparison and analysis for cloud units, which are based on regional rainfall data and radar data, respectively. The results show that the consequences about the effect of the two cases are positive deviations, and both precipitation effects have passed the significance test. The reason for the precipitation enhancement effect difference between the daily precipitation data and hourly rainfall data may be that the gap of the two kinds of data is larger in spatial and temporal distribution, and the selected operation periods of the two kinds of rainfall data are not in the same length. Through comparing physical parameters between the seeded cloud units and the unseeded cloud units, which are similar to those seeded detected by radar before and after the operation, an obvious positive deviation is found. So, the radar detection evidence of precipitation enhancement is provided. The radar detection results are consistent with the regional historical regression results in the two cases. The variation trends of the two cases are consistent and both of the two cases have positive deviations.