Abstract: The idea and procedure for developing high efficient AgI pyrotechnics used in weather modification are given in this paper. Two formulations (BR-88-5 and BR-91-Y) of pyrotechnic with high nucleating effectiveness have been obtained after a number of screen tests carried out in 2m3 cloud chamber. The effectiveness can reach up to 1015/g AgI in the temperature range of -7.5—20℃ and the nucleating rate is very high for BR-91-Y. The foreign pyrotechnics were made according to the given formulations of Silverspare (USSR) and TB-1 (USA),their ice nucleating properties have also been tested in the same chamber for comparison with the new pyrotechnics. The aerosols produced by the new pyrotechnics as the hexagonal crystal form of AgI have been identified by the X-ray powder diffraction analysis and proved to have the closest match to ice.