The transformation and environmental characteristics of natural radionuclides in a coal‐fired power plant were investigated. The coal, bottom ash, fly ash, and soil samples were collected. The activity concentrations of natural radionuclides (226Ra, 232Th, and 40K) were determined by a high‐purity germanium gamma ray spectrometer. The radiological hazard factors include radium equivalent activity, external hazard index, air absorbed dose rates, and annual effective dose that were used to evaluate the potential environmental and health risk. The results show that these natural radionuclides are enriched in bottom ash and fly ash during coal combustion. The activity concentrations of these radionuclides at the southeast and northwest soil samples are generally higher than those of the southwest and northeast. 226Ra is mainly enriched at the distance of 200 m, while 232Th is primarily higher in the power plant. Based on the radiological risk assessment, the environmental effect of natural radionuclides caused by coal‐fired power plant is considered to be negligible because the radium equivalent activity and external hazard index values of the measured samples are below the acceptance limitations of 370 Bq kg−1 and 1. The bottom ash and fly ash could be used as construction materials under high management and regularization. © 2015 American Institute of Chemical Engineers Environ Prog, 34: 1080–1084, 2015