Abstract: Two kinds of Fe-bacteria(named Fb₁ and Fb₂) were s eparated from the natural water samples collected from the west district of Jilin province. Fb₁ is ellipse and its cells array in pairs and the size is 0.7~1 μm. Fb₂ is bacilliform and its cell is single or connected eac h other and the size is (0.4~0.7) μm×(1.5~2.1) μm. They are both Gram-negative bacteria. Fb₁ has spore, while Fb₂ has not any. Fb_{1 can be mobile through their flagellum, but Fb2 can not be because they have not flagellum. These two kinds of Fe-bacteria live in the water samples with a large quantities. They entered the stationary phase when they were developed in the culture medium of beef extract and peptone for 20 h, and they entered the decline phase after 24 h. The results indicate that their physiological and biochemical properties are similar.}

Key words: the west district of Jilin province, natural water, Fe-bacterias, ultrastructure, scanning electron microscopy