Chlamydia psittaci ( C. psittaci) is an obligate intracellular bacterium that replicates in neutrophils, a significant producer of reactive oxygen species(ROS). However, the effect of ROS on C. psittaci infection and whether C. psittaci regulates ROS production in neutrophils is unclear. When C. psittaci infects neutrophils, it can induce the production of a small amount of ROS, affect the assembly of NADPH oxidase through p38/ERK signaling pathways, and actively block the ROS produced by PMA-stimulated neutrophils. Importantly, this study may provide new insights into the molecular pathogenesis and immune escape of C. psittaci.