Analyzing the 13 sort contents of broccoli leaves by using GC/MS, sulforaphane was found in 11 sort of broccoli leaves for the result. After being grinded by the blinder, amount of sulforaphane in broccoli leaves was rapidly raised after thirty minutes and maintained the amount till sixty minutes have passed. Among the parts of broccoli, the root had the most sulforaphane. In freezing temperature, biosythesized sulforaphane maintained longer than in room temperature. However, even in frozen condition, the amount of sulforaphane was reduced to half or less after 3 weeks.