【Background】The arthropod community is an important part of farmland ecosystems. The effect of transgenic crops on the structure and biodiversity of arthropod communities in the fields is one of the important subjects of the environmental safety evaluation. Phytase transgenic maize was the first transgenic crop that was issued a bio-safety certificate in China. 【Method】By using direct observation method, the species and population of the most common arthropod groups were investigated regularly in 3 experimental treatments including phytase transgenic maize 10TPY005 plot, its non-transgenic parent Liyu 35 plot and local corn variety Zhengdan 958 plot. The effects of phytase transgenic maize on the biodiversity of arthropod communities were studied by analyzing diversity index, evenness index and the Berger-Parker dominance index of the whole arthropod community, the natural enemy, and pest sub-communities. 【Result】There was no significant difference in any of above community indices between phytase transgenic maize 10TPY005 and its parent Liyu 35. The index dynamics of the arthropod community living in phytase transgenic maize 10TPY005 and its parent Liyu 35 were also similar. 【Conclusion and significance】In the short term, the phytase transgenic maize did not significantly affect on the biodiversity of arthropod communities in cornfield.