Abstract: Objective 　To detect the reliability of near2inf rared parameters of blood oxygen of mammary gland phyma f rom the microvessel density of tumor. Methods 　181 cases of mammary gland pryma who had accept the examination of the near-infrared TBO-I dual-wave length mammary gland phyma dedecfor were classified by near2inf rared parameters of blood oxygen, and were performed the pathologic exmination to ascertain whether tumor is benign or malignant . Out of these cases, int ratumor microvessel density of 20 cases of malignant phyma and 20 cases of benign phyma were confirm by s2p immunohistochemical methods, then the relation among near2inf rared parameters and microvessel density were analyzed by medical statistics. Results 　(1) The microvessel density and blood concent ration of 28 cases of the“high blood”tumor was 24. 56 ±8. 110, 1. 891 ±0. 850 respectively. The microvessel density and blood concent ration of 12 cases of the“low blood”was 17. 98 ±8. 729, 0. 698 ±0. 283 respectively. There is significant difference between the“high blood”tumor and“low blood”tumor. ( P < 0. 05) . (2) The int ratumor microvessel density and blood concert ration is linearly correlated respectively, the linear correlation coefficient r =0. 4208 ( P < 0. 05) in 40 cases of mammary gland phyma. Conclusion 　The int ratumor microvessel density of benign or malignant mammary gland phyma and blood concent ration is linearly correlated. Blood concent ration (one of near2inf rared parameters) is reliable to be used as dignosis criterion of malignant mammary gland phyma.