【Objective】This study was carried out to reveal the response of paddy soil anammox bacterial activity, abundance and community structure to rice straw returning and different tillage practices, which may provide scientific basis for nitrogen (N) management of paddy field. 【Method】Three different till treatments (conventional till, rotary till and no till)+rice straw returning were set up, respectively, with conventional till but no rice straw returning as control. The potential activity, functional gene (hzsB) abundance and community structure of anammox bacteria were analyzed by _¹⁵N tracing, fluorescent quantitative PCR and Illumina sequencing, respectively.【Result】Anammox activity showed significant difference and the values could be ranked as no till > rotary till > conventional till (p<0.05), while no significant difference was observed between control and rotary tillage+rice straw. No significant difference was detected in copy number of hzsB among treatments. Two known anammox bacteria (Kuenenia and Scalindua) and some unidentified genera were identified by Illumina sequencing, and the relative abundance of Kuenenia and Scalindua showed negative correlation (p<0.05). Pearson correlation analysis showed that anammox activity was significantly correlated with denitrification activity, but not with hzsB abundance and community composition. 【Conclusion】 We conclude that anammox activity and community composition, but no the functional gene abundance, respond to long term straw returning and different tillage practices. Rice straw returning+conventional till in rice field may inhibit N loss to some extent, while rice straw returning+no tillage increased soil N loss potentially.