Based on the monitoring data of main greenhouse gases, variation characteristics of carbon dioxide (CO₂) and methane (CH₄) in Changzhou from 2016 to 2020 were studied by using such methods as longterm sequence analysis and correlation analysis. A correlation between the concentration of CO₂ and CH₄ and pollutants and meteorological parameters was analyzed, and the effects of biological sources and human activities were discussed preliminary. The results showed that the annual average concentrations of CO₂and CH₄were 416.4ppm and 1635.7ppb in Changzhou respectively, and the increasing rates were both higher than that in Waliguan during the same period. The CO₂and CH₄ concentrations were lower and the biological sources such as photosynthesis and plant growth had a greater impact in summer. While the concentrations and impacts of human activities and industrial production increased in winter. The diurnal variation of CO₂ concentration showed two peaks in the morning and evening. The diurnal variation of CH₄ exhibited one peak and it was highest in autumn which indicated the greater impact of biological sources on CH₄. CO₂ and CH₄ were significantly correlated with NO₂, NOx, PM_2.5and PM₁₀. The correlation with meteorological parameters was obviously weakened. When the wind speed increased, the diffusion conditions were conducive to the reduction of CO₂ and CH₄ concentrations.