Based on the observations from 14 stations in Liaoning Province and the radiosonde data from Shenyang Station, analysis is conducted on the occurrence frequency of various cumulus and its precipitation characteristics from June to August, as well as the precipitation probabilities of various cumulus and their potential affected by artificial. The results indicates that: (1) The probability of the cumulus emergence is very high in summer in Liaoning, the annual average rate is 41.5 days and it is over 50% of the total cloud days in summer. (2) There is more than 11 rainy days caused by cumulus on average, and it is 36.9% of the total rainy days in summer. (3) The area averaged cumulus precipitation is 33.5% of the total precipitation, in which the rainfall produced by cumulus heavy rains is 43.1% of the total. (4) The probability of cumulus along with stratiform clouds is quite high, but the precipitation efficiency is not very high in most of situations. There is quite high potential and a great deal of operation opportunities for rain enhancement in Liaoning Province