Based on Ozone （O3） Monitoring Instrument satellite remoting sensing data and reanalysis meteorological data, an analysis was conducted on the spatiotemporal distribution and trends of tropospheric nitrogen dioxide （NO2） and formaldehyde （HCHO） in Guangdong Province from 2015 to 2020. The study also examined the changing characteristics of O3 generation sensitivity in relation to meteorological parameters. The results indicated that during 2015-2020, the tropospheric NO2 column concentration in Guangdong Province exhibited a distribution pattern with the Pearl River Delta （PRD） Region as the high-value center gradually decreasing towards the surrounding areas, with the most substantial decline observed in the Pearl River Delta. The HCHO column concentration showed a pattern of higher values in the PRD and lower values in the other regions. While most areas exhibited a decreasing trend in HCHO column concentration, the spatial distribution was more dispersed compared to that of NO2. In most regions, the ratio of HCHO to NO2 （FNR） showed an increasing trend. The area under VOCs-NOx synergistic control decreased, whereas the area under NOx control increased. By 2020, the proportions of VOCs control area, VOCs-NOx synergistic control area, and NOx control area in Guangdong Province were 0.5%, 13.1%, and 86.4%, respectively. The FNR value showed an increasing trend； a positive correlation with 2 m temperature, relative humidity, downward surface shortwave radiation, and boundary layer height； and a negative correlation with 10 m wind speed and sea level pressure. The three most influential meteorological factors were downward surface shortwave radiation（DSSR）, relative humidity, and 2 m temperature, impacting the FNR value the most.
Keywords: Guangdong Province; O3 generation sensitivity; meteorology; ratio of HCHO to NO2（FNR）; satellite remote sensing.