Since 1987,the biological characteristics of INA bacteria and their relationship with frost have been thoroughly studied in the institutes of Plant Protection and Agricultural Meteorology of CAAS under the consecutive support of the National Natural Sciences Foundation of China. In this paper,the research progress both in China and abroad was reviewed.From 68 species of plants in 17 provinces or cities of China,250 strains of INA bacteria were isolated and calssified into 17 species or pathovars of 3 bacter...