This study is to find out the histopathological characteristics of lymph node sinus containing blood. Routine autopsy was carried out in the randomly selected 102 patients(among them,100 patients died of various diseases, and 2 of non-diseased causes),their superficial lymph nodes locating in the bilateral neck, axilla, inguina, thorax and abdomen were sampled. Haematoxylin-eosin staining was performed on 10% formalin-fixed and paraffin-embedded lymph node tissue sections(5μm).The histological characteristics of the lymph node sinuses containing blood were observed under light microscope. Among the 1362 lymph nodes sampled from the 100 autopsies, lymph sinuses containing blood were found in 809 lymph nodes sampled from 91 cases, but couldnt be seen in the lymph nodes sampled from the non-diseased cases. According to histology, five kinds of lymph sinuses containing blood were found:vascular-opening sinus, blood-deficient sinus, erythrophago-sinus, blood-abundant sinus, and vascular-formative sinus. It is concluded that in the state of disease, the phenomenon of blood in the lymph sinus is not uncommon. Blood could possibly enter into lymph sinus through lymphatic-venous communications between the veins and sinuses in the node. Lymph circulation and blood circulation could communicate with each other in the lymph sinus.