Abstract: In order to reasonably evaluate heavy metal pollution in urban green land soils, 180 soil samples (0-15 cm depth) from the surface of urban green land in Nanjing were collected based on the grid method, and the contents of Cu, Pb, Zn, Cr, Cd and As were measured. Hakanson toxic response coefficient in the system were used to show the toxicology properties of the heavy metals. A modified traditional overweighting method was used to show the potential harm from heavy metals. The matter-element extension model was used to evaluate the comprehensive pollution level of 6 kinds of heavy metals, the assessment result of which was compared with that of the Nemerrow pollution index method. Results showed that the weights of heavy metals as amended by the Hakanson toxic response coefficients were adjusted to some extent; among them, the weights of Zn, Cr, Cu, Pb and As decreased by 92.9%, 85.1%, 68.9%, 61.5% and 23.2%, respectively, whereas the weight of Cd, with high toxicity, increased about 130%, which more fully reflects the toxicological properties of the heavy metals. Evaluation of the matter-element extension model showed that the pollution value due to heavy metals from Nanjing urban green land soils was 2.481, at level Ⅲ (light pollution), but some samples had higher pollution values, at level Ⅳ (moderate pollution). The spatial interpolation of pollution values showed that the moderate pollution was concentrated in the northern traffic-intensive areas and western industry-intensive areas, with serious man-made pollution. The evaluation of the matter-element extension model was basically consistent with the assessment by the Nemerrow pollution index method, and was more accurate, which verified the reliability of the matter-element extension model in soil heavy metal pollution assessment.