Abstract： Objective To compare the results of three phase bone scans between benign and malignant lesions, and explore its clinical value. Methods Patients with pain symptom underwent three phase bone scan. Their corresponding clinical data was collected and input into SPSS software package for further evaluation. Results Forty-nine patients had 73 positive foci in the acquiring field of vascular and blood pool phase bone scans. Excluding 10 foci that suspected of bone metastasis, 37 of 63 were malignant,26 were benign lesion. On vascular, blood pool and delayed images, benign and malignant foci did not exist any significant difference (χ2 =3.341, 1.685 and 2.923, P ＞0.05). In these lesions, 33.3 % (5/15) foci had positive vascular and blood pool results in thoracic, 72.2 % (13/18) in extremity and 75.0 % (18/24) in pelvic.There were no significant difference among subgroup of chest, abdomen, limb and pelvic diseases. In addition,4 foci outside bone system were occasionally found in three phase bone scans. Conclusion Acquiring position could significantly affect the results of three phase bone scan, for example more sensitive rate can be found for limb and pelvis lesions. This method could not significantly differentiate malignant from benign lesions, but could detect soft tissue foci or the change of blood flow, and provide more information for differential diagnosis.