Objective To discuss the value of early dynamic contrast-enhanced MR imaging Slope histogram to evaluate neoadjuvant chemotherapeutic response of osteosarcoma. Methods Conventional and early dynamic contrast-enhanced MR imaging were performed in 14 patients with pathologically confirmed limb osteosarcoma at two time points: within 3 days before neoadjuvant chemotherapy, and within 3 days before surgery after neoadjuvant chemotherapy. Slope maps before and after neoadjuvant chemotherapy were obtained using built-in workstation processing software. Slope histograms were obtained using a Matlab-based customized software. The patients were divided into the good response group and poor response group according to postoperative Huvos grading pathologically. The change of pre- and post- neoadjuvant chemotherapy Slope histogram and mean Slope value between the two groups were compared. Results The mean value of Slope histogram was obviously shifted to the left in good response group (6 patients). However, the mean value of Slope histogram did not obviously shift to the left or even shift to the right in the poor response group (8 patients).The change of the mean Slope value pre- and post-neoadjuvant chemotherapy was statistically different in the two groups (P=0.008). Conclusion The Slope histogram is helpful for evaluation of neoadjuvant chemotherapeutic response of osteosarcoma.