Abstract: To study the ¹⁴C levels in the food samples and botanic samples (moss and pine needle) which were distributed in the radius of 6.5 kilometer, ¹⁴C specific activity was measured using accelerator mass spectrometry (AMS). The ¹⁴C specific activity in moss samples, which ranges from 223.0 to 265.6 Bq/kg C, decreases with increasing of the distance from the stacks of Plant Ⅲ (heavy water reactor) and reaches to the background (223.8 Bq/kg C) at a distance of 6.5 km. Compared to pine needle sample, moss sample is a better indicator to investigate the ¹⁴C distribution close to Qinshan Nuclear Power Plant. The ¹⁴C specific activity distribution in moss samples shows that the diffusion of the ¹⁴C pollutant discharged from the Qinshan Nuclear Power Plant is affected by the geographical and meteorological conditions. The excess ¹⁴C specific activities in the food samples range from 8.5 to 13.0 Bq/kg C (except for rice samples), resulting a radiation dose of 0.5 μSv/a to the public.