Objective To observe ultrasonic and PET/CT features of malignant lymphoma after chemotherapy and to determine the value in assessment of lymphoma treatment response.Methods Seventy-seven lymph nodes in 32 patients were observed and measured with color Doppler ultrasound and PET/CT after chemotherapy comparing with pathologic results.Results Seventy-two lymph nodes were exactly certified by ultrasound(94.8%),and seventy-five nodes were exactly confirmed by PET/CT(97.4%).There were significant differences in L/S,blood supply type,Vmax,Vmin,RI(P＜0.05)between nodes groups with and without residual tumor.The PET/CT inspection demonstrates that lymph nodes with residual tumor was in the high metabolism condition.The positive nodes'index of ultrasound were connected with their metabolism condition.Conclusions The two methods all have high rate of accuracy.Ultrasound can be used as normal method in assessment of lymphoma treatment response.