The banana weevil, Cosmopolites sordidus, is the most important pest of banana in the world. The effect of the pheromone releasing measure, a kind of ecological control method, was investigated over 2 years in Nanbao Farm, Lingao county, Hainan, China. The pheromone used was Cosmolure+, a commercially available C. sordidus aggregation pheromone. There were 3 treatments, including 0, 5 and 10 pheromone traps/ha. Pheromone lures were changed monthly at which time the traps were moved to a different location within the stand. There were no significant differences in mean catches of C. sordidus per trap in the most of the investigation period except September 2009. Meanwhile, there was no significant difference in plant damage between the pheromone treatment of 5 traps/ha and 10 traps/ha. The results also showed that the relationship between the mean number of weevils caught per month and average rainfall was not significant. Possible reasons for the 5 traps/ha efficacy in this study are discussed.