Objective： To investigate the potential clinical value of Chinese ink as a tracer in dye-directed sentinel lymph node biopsy. Methods： Forty-two female rabbits were randomly divided into 7 groups. The breast drainage lymphatic vessels and nodes in axilla were exposed by surgery. Under the papillae of the second pair of breast, 0.1 mL Chinese ink dilution at concentrations of 0.1%, 1%, 10%, 50% and 100% and isosulfan blue （IB, 1.0%） were injected. The movement of ink in lymphatic chain was investigated, and the number of stained nodes and their staining and washout time ware recorded. The first stained lymph node that was followed through lymphatic drainage was identified as the sentinel lymph node （SLN）. The SLNs were dissected and prepared for histological observation 5 rain, 1 h and 2 weeks after stained. Blood samples were harvested and tested before and 2 weeks after injection. The hearts, lungs, livers and kidneys were dissected after a period of post-operation observation and sent for pathologic examination. Results： No obvious differences were observed among the staining time of SLNs and the second lymph node using ink at different concentrations （P〉0.05）. But they were obviously longer than that of IB （P〈0.05）. The mean number of nodes obtained was nearly the same （P〉0.05）. It was too light for gross visual inspection when nodes were stained by ink at the concentration of 0.1%. Nodes stained by IB faded 33.9 rain after stained. And carbon staining seemed permanent without any visible decline after 2 weeks. Carbon particles were found to be in the sinus of lymph nodes that were obtained 5 rain after stained, and then was phagocytosed by macrophages （MФ） 1 h later. The density of carbon obscured the microscopic observation of lymph nodes when they were stained using Chinese ink at concentration of higher than 20.0%. No obvious changes were investigated in blood test and vital organ pathologic examination. Conclusion： Chinese ink is potentially a novel type of dye trace
