Objective To evaluate hemodynamic status,pathological,imaging and ultrasound changes of residual lymph nodes from diffuse large B-cell lymphoma (DLBCL) after chemotherapy and their relationship with clinical treatment after chemotherapy.Methods 50 DLBCL patients undergoing full course of chemotherapy but still bearing residual lymph nodes were examined with ultrasound-guided lymph node biopsy.Some examinations were combined with PET-CT to analyze properties of residual lymph nodes.Results 64 lymph nodes were identified by color Doppler ultrasounda in the 50 DLBCL patients treated with full course of chemotherapy.Among them,53 lymph nodes from 42 patients did not show artery blood flow and HE staining of these lymph node biopsy met the clinical standard for complete remission.For the other 11 lymph nodes from 8 patients,ultrasound examination displayed smrounding blood flow inside.At the same time,PET-CT showed that these lymph nodes had higher SUV values,implying high metabolic state in these tissues,which was in agreement with ultrasonic examination results.However,HE staining of these lymph nodes biopsy demonstrated only residual lesion but no tumor tissue.Conclusions Lymph nodes still exist in DLBCL patients treated with full course of chemotherapy.Ultrasound and PET-CT examination have high accuracy in diagnosing benign and malignant residual lymph nodes in follow-up examination on 4 weeks after chemotherapy showed that lymph nodes are over ＞ 1.5 cm in length and have central or peripheral blood flow.Therefore,PET-CT examination of tumor could be considered as a reference index in characterizing residual tumors after chemotherapy.