In a field experiment, possible effects of transgenic Bt rice on arthropod communities under paddy field conditions were assessed for 3 yr in terms of arthropod guild dominance, family composition, dominance distribution of each guild, individuals of each guild, and community indices (including Shannon-Weaver diversity index and dominant concentration index). Our results overall suggested no significant differences between the Bt and control rice plots in these arthropod community-specific parameters. The similarity of arthropod communities in the Bt and control rice plots was apparently high. Based on our findings, we conclude that Bt rice generally exerts no marked negative effects on the arthropod community in paddy fields.