Abstract: Agriculture is greatly benefited from biochar that is used as a soil enhancement. However, much attention needs to be paid to the potential adverse impacts on the environment due to biochar-borne contaminants. Biochars were produced from rapeseed cake under anoxic/anaerobic conditions at temperatures between 200 and 700 ℃. The concentrations of polycyclic aromatic hydrocarbons (PAHs), heavy metals and minerals in biochars were determined, and the environmental suitability of biochars for land application was assessed. The results showed that the total PAHs concentration was 0.2-3.4 mg/kg. The total heavy metals and minerals were found at the following concentrations (mg/kg):Cu, 8.9-23.3; Zn, 149.9-372.1; Pb, 1.1-1.9; Cd, <0.014; Cr, 6.3-14.8; Ni, 5.9-14.0; Fe, 140.6-462.1; Mn, 86.8-269.2. The total concentrations of PAHs and heavy metals in all biochars were below the control standards of sludge for agricultural use in China, the USA and Europe (minimum standards of PAHs, Cu, Zn, Pb, Cd, Cr, Ni in these countries are 6,0, 500,0, 5,0, 100 mg/kg, respectively). The mass concentrations of leachable Mn in some biochars exceeded the groundwater or drinking water standards of these countries (minimum standard was 50 μg/L). Overall, biochars generated at high temperatures (500-700 ℃) were suitable for land application due to their low total PAHs contents and mass concentrations of leachable elements.