AbstractPM2.5 plays a key role in the solar radiation budget and air quality assessments, but observations and historical data are relatively rare for Beijing. Based on the synchronous monitoring of PM2.5 and broadband solar radiation (R_s), a logarithmic function was developed to describe the quantitative relationship between these parameters. This empirical parameterization was employed to calculate R_sn from PM2.5 with normalized mean bias (NMB) −0.09 and calculate PM2.5 concentration from R_sn with NMB −0.12. Our results indicate that this parameterization provides an efficient and straightforward method for estimating PM2.5 from R_s or R_s from PM2.5.