Strain XD20 was an endophytic strain with nitrogen fixation activity isolated from sugarcane roots. In this experiment, 16S rDNA identification and nifH gene amplification were carried out, and its growth promoting characteristics, such as nitrogen fixation, phosphorus dissolving, ferritin production and indoleacetic acid (IAA) were analyzed. Meanwhile, the growth promoting effects on sugarcane after inoculating were also studied. The results showed that: (1) strain XD20 was identified as Pantoea agglomerans by 16S rDNA gene sequence. (2) About 360 bp was amplified by universal primer polyF/polyR of nifH gene, and the nitrogenase activity of the strain XD20 was 3 187.8 nmol·mL^-1·h^-1 by using acetylene reductase method. (3) Strain XD20 had an ability to produce IAA, which the concentration of IAA reached 36.71 μg·mL^-1, and also can dissolve organophosphorus and produce ferritin. (4) Inoculating the strain XD20 to different varieties of sugarcane (B8, ROC22 and GT40), increased the plant height, plant biomass, chlorophyll content in leaves, nitrate reductase activity, glutamine synthase activity and nitrate nitrogen content of three sugarcane cultivars at varying degrees, and the promoting effect of B8 was the most significant.