The presence of concomitant bacteria on the capsular surface of obtaining pure cultures of Azotobacter from the cultivated soils introduced difficultied of Canton. Concomitant bacteria associated with Azotobacter include Pseudomonas azotogensis, Azotomonas insolita, Pseudomonas flourescens and Pseudomonas sp., Pseudomonas axotogensis, also a kind of nitrogen-fixing bacteria, are found is most cultivated soils in Canton, and are present in a larder number than Axotobacter.