The vascular architecture of bone giant cell tumor was observed histologically with resin cast technique and scanning elec tron microseopy. Three types of capillaries were noted in the tumor tissue: extruding club-like capillary in the outer zone of the tumor; sinusoid capillary running disorderly in the intermediate zone; cecum capillary in the central zone. The pattern of vascular structure was believed to be correlated with tumor growth. The vascular architecture of bone giant cell tumor was observed histologically with resin cast technique and scanning elec tron ​​microseopy. Three types of capillaries were noted in the tumor tissue: extruding club-like capillary in the outer zone of the tumor; sinusoid capillary running disorderly in The intermediate zone; cecum capillary in the central zone. The pattern of vascular structure was believed to be correlated with tumor growth.