We evaluated the environmental safety of the transgenic RRM2 (RNA recognition motif 2) cotton on insect communities in the Changjiang River Ecological Zone. From 2013 to 2015, we recorded and systematically monitored the structure and composition, community characteristics, diversity, abundances and seasonal changes of the insect community, pest sub-community and natural enemy sub-community in the transgenic cotton fields. We found that the composition of main functional groups in transgenic cotton fields was similar to non-transgenic cotton fields. The transgenic RRM2 cotton fields had significantly higher aphid numbers than non-transgenic cotton field in 2013. In comparison, the number of cotton spider mite, cotton bollworm and other Lepidoptera were markedly lower in transgenic RRM2 cotton field than in non-transgenic cotton field in 2013. There was no significant difference in the other two years and other functional groups. We also found that abundances of insects increased, but species richness decreased, in the transgenic RRM2 cotton fields compared to the non-transgenic cotton fields during pest outbreak years. However, there was little difference of individual numbers and species richness of insect community in transgenic RRM2 cotton fields relative to non-transgenic one, but differed significantly during three years. Indices of diversity, evenness and dominance of insect community and pest sub-community did not vary by cotton type during years, the same as that of natural enemy sub-community except for that in 2013. Although there were seasonal fluctuations in the number of individuals and community characteristics of insect community, pest sub-community and natural enemies, these temporal dynamics did not vary between the RRM2 gene cotton fields and non-transgenic cotton fields. However, during peak abundances, indices of diversity and evenness of communities were at their lowest, while the reverse was true for index of dominance. Seasonal fluctuations were obvious with the insect community and pest sub-community, but that of natural enemy community varied more moderately across seasons. Overall therefore, RRM2 transgenic cotton did not significantly differ from non-transgenic cotton fields in insect community structure and composition and temporal dynamics of community characteristics, but the occurrence of insect pests in RRM2 transgenic cotton field might increase in years with suitable climate.