The implementation of operational monitoring atmospheric reactive gase s is one of the important goals of atmospheric composition observations sponsore d by the China Meteorological Administration. Quality control to meet the requir ements of reactive gas monitoring at regional atmospheric background stations ar e studied based on the twoyear practical experience at Longfengshan Station. Historical zero/span checks and multipoint calibrations are analyzed and the guide of their operating frequencies including zero/span a djustment is provided. The process of data correction based on the quality contr o l information, standard traceability process and instrument equipment testing, i nspection, and maintenance are also provided. The experience and problem related to the quality of monitoring in the operation are summarized. The necessity and measures for quality control during routine operation and data correction are d iscussed. Suggestions, especially the needs to strengthen the capability of the information analysis provided by quality control for people on duty, are given f or further improvement of the quality of observation.