This study investigates the spatial distribution and source contributions of fine particles (PM_2.5) in complex terrain in Jincheng, China, using the Weather Research and Forecast (WRF) Model/California Puff Model (CALPUFF) modeling system. To evaluate the CALPUFF performance, the simulated results were compared with the observational data at the three monitoring stations. The results show that the CALPUFF simulation results underestimate the daily average concentration of PM_2.5, and the statistical analysis also reveals an underestimation trend. The spatial distribution shows that PM_2.5 concentrations decrease gradually outward from the Jincheng city center. Primary PM_2.5 concentrations in December are significantly higher than those in July. However, the concentrations of secondary sulfate ions (SO₄²⁻) and nitrate ions (NO₃⁻) in July are higher than those in December. In December, residential heating was the main contributor to the PM_2.5 concentration, accounting for 50%, and industrial processes and dust (an anthropogenic dust from construction processes, open yards and roads) accounted for 18% and 14%, respectively.