Kunming is a typical city of plateau basin with water supply mainly from surface water. The heavy metal of air pollution comes into ground which influences the surface environment severely and threat the security of water supply of Kunming.Based on the samples of rainwater from October 2013 to September 2014 of Kunming, the paper analyzed 8 common heavy metals with atomic fluorescence and ICP-MS mass spectrometer. pH value and measured the conductivity of local precipitation.The results indicated that pH value is approximately 8.36, which is oriented to alkaline, the highest peak of conductivity is 27.6μS/cm and appears in February, and the minimum value is 13.4μS/cm and appears in July. The correlation between conductivity and rainfall is negative. According to the water environment quality standard (GB3838-2002), the content of Hg and Cr is levelⅠ, the content of Cu, Cd and Pb is level Ⅱ, and the content of Zn and Ni is beyond levelⅤ. The content of Ni, Zn, Pb and As was all beyond the Hygienic Standard for Drinking Water (GB 5749-2006) in different levels. The concentration of heavy metal was higher in the north part of the city, which has more population, than in the south part of the city. The water resources environment and safety affected by contamination of heavy metal in rainwater of Kunming will become a key concern.