Abstract: Pyrotechnics flares, containing silver iodide (AgI) as active ice-nuclei (IN), are widely used for seeding in hail suppression and precipitation enhancement operations over China nowadays. The idea and procedure for developing newly high efficient AgI pyrotechnics widely used in weather modification in China are given. The different nucleation mechanisms are strongly depended on the size of the nuclei aerosols. Furthermore, it must be known how long it is possible to work with one and the same aerosol before coagulation has seriously altered the spectrum. Five formulations of pyrotechnics with high nucleating effectiveness, containing 1.5%—5% by weight of AgI, including the flare is made according to the given formulation of silver spare (USSR), are examined their particle size with the environmental scanning electron microscope FEI Quanta 200 (ESEM) and transmission electron microscope (TEM). At the same time, their nucleating effectiveness and temperature thresholds are tested. The characteristics of five kinds of AgI-type pyrotechnics are investigated and compared with other widely used product-silverspare, or A2 USSR.From the electron microscopic analyses, the size distributions of the particles produced from all five types of flares are found to be similar. For each of pyrotechnics, more than 98% of AgI effluent concentration is contained in particles less than 0.5 μm in diameter, and more than 90% is contained in particles less than 0.3 μm. Because of the particle sizes, a diffusive contact and condensation-freezing mechanism is probably playing an important role in the nucleation of water droplets. Different kinds of AgI-type pyrotechnic has differ size distribution. Based on TEM micrographs or five kinds of AgI-type pyrotechnics particles, several less AgI particles adhered on a KCl particle and the structure characteristics is maybe the cause that resulted in a high nucleating effectiveness. The AgI contents and temperature thresholds of five kinds of pyrotechnic nucleate and Ice crystal formation kinetics for AgI aerosols in the isotherm al cloud chamber at given temperature are studied in the research. For five kinds of AgI agents, their thresholds temperature change in the range of -4.4—-3.5 ℃. Their differences are less, in other words, the temperature thresholds of AgI pyrotechnics are mainly decided by AgI itself. The interaction of cloud, CCN and AgI artificial ice nuclei (AAIN) is important to the formation of cloud, precipitation and weather modification. The size distribution of AgI effluent from the five flares appears to be similar based on the carbon membrane samples that are collected static subsidence and analyzed with an ESEM. The deactivation of AgI smoke in contact with liquid water above -4.4 ℃ is considered, it therefore should not be introduced for cloud-base seeding at warm temperatures. The chemical composition of the pyrotechnic is another important factor that directly affects the effectives and nucleating mechanism of the AgI pyrotechnics. In the future research, the experimental study on the chemical composition of flares at the main mode is helpful to interpret the nucleating effectiveness differences in the flares. The interrelation of them is complex and further study is needed.