Objective To observe the pharmacokinetics and concentration of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) in brain tissue after BCNU-polylactic acid (PLA) delayed release wafer embedded in brain tissues of dogs.Methods 10% BCNU-PLA delayed release wafer were prepared and embedded in brains of 12 dogs. Peripheral blood of dogs was taken and the animals were executed for brain tissue after surgery in different times. BCNU concentrations in blood and brain tissue were quantified by high-performance liquid chromatography.Results BCNU was able to be detected at 22nd hour, and the Cmax (average 243.64 ng/ml) appears at 35th hour after surgery. The average BCNU concentration in brain tissue was 26.60 μg/g at 5th day after surgery.Conclusion BCNU-PLA delayed release wafer is a useful type for treatment of malignant gliocoma.