Abstract: A study was conducted to evaluate the efficiency of entophytic diazotrophs inoculation. Three representative types of endophytic diazotrophs with the highest, moderate and the lowest nitrogenase activity were selected out from endophytic diazotrophic bacteria isolated from wild Cynodon dactylon. T-419 hybrid bermudagrass (Cynodon dactylon×Cynodon transvaalensis) were inoculated with these three representative bacteria using three inoculation methods (microbial soaking, microbial soaking+irrigating bacteria 6 times and microbial soaking+irrigating bactera 12 times). After inoculation, the plants were planted in pots with urea and no urea as control to examine the efficiency of inoculation methods and the response of T-419 hybrid bermudagrass. The results indicated that Bm bacteria liquid with moderate nitrogenase activity had more influence on nitrogenase activity of aboveground parts of T-419 hybrid bermudagrass compared with the other inoculated bacteria and the control. The inoculation method of microbial soaking is most effective method compare with the other two which induced higher nitrogenase activity of aboveground parts of T-419 hybrid bermudagrass. It was concluded that microbial soaking is optimal for inoculation of endophytic diazotrophs with hybrid bermudagrass. However, the effects of inoculation methods on density of endogenous azotobacter nitrogenase were not significant. Urea treatment has no significant influence on endogenous azotobacter nitrogenase activity and density of bacteria of aboveground parts of T-419 hybrid bermudagrass.