Weather modification operations in China has been carried out since 1958 with silver iodide as the main seeding agent. Whether silver iodide affects the environment has attracted much attention. This paper analyzed the content of silver ions in precipitation, soil and lakes after silver iodide seeding in several countries in the world. The amount of silver iodide used in China was counted, and silver ions in precipitation and in the reservoir were measured. It is found that the silver iodide used for weather modification in China do not affect water resources and the environment.