The distribution and content differentiation of morusin in the cultivated species of mulberry by HPLC-DAD are described in this paper. The experimental results showed that morusin is present in all parts of the mulberry bush. The content of morusin was highest in root bark and second highest in branch bark. The difference in morusin content of 20 different species of cultivated mulberry branch bark was significant. The level of morusin was highest in the branch bark of cultivated mulberry No. 404, a tetraploid cultivar, and third in the Husang 32 cultivar of Morus multicaulis. The method used in this study for determining morusin content exhibited good repeatability (RSD 6.02%) and recovery (100.62%). Therefore, the results from this study provide reliable data, for research and development in the future, on the level and distribution of morusin in mulberry in general and the differences found between various cultivated mulberries in particular. Furthermore, the HPLC-DAD method to determine morusin content is fast and reliable and is applicable not only to mulberry bushes but also to other plants.