Effects of Foliar spray of Kinetin on the growth and metabolism of mulberry tree was investigated in this studies. The results are summarized as follows; 1. Appropriate level of Kinetin for the optimal growth of mulberry tree was 100ppm. 2. In the non-fertilizer, N, P, K, and N+P+K treated plots supplemented with Kinetin, the growth of mulberry tree was generally promoted, especially in the roots, in comparison to non-supplemented plots. The effect was notably outstanding in the N, and N+P+K treated plots. 3. The mechanism by which the growth of root is stimulated was fundamentally attributed to the hypertrophy of unit cells. 4. The chlorophyll contents of the leaves in the Kinetin supplemented plots were higher than that of the non-supplemented, especially in the N, and N+P+K treated ones. 5. Likewise, total sugar contents of Kinetin supplemented plots were higher than that of the non-supplemented. Particularly the N+P+K treated plots showed higher level of sugar contents. In other plots, there were no significant differences in the level of sugar contents. 6. The activity of GOT and GPT was higher in the Kinetin supplemented plots, particularly in the N, and N+P+K treateated. 7. The contents of ascorbic acid were increased in plots with kinetin supplement in the order of N+P+K>potassium>Nitrogen>phosphorus$geq$non-fertilizer. 8. Difference between Kinetin treatment and non-treatment was not recognized in the contents of inorganic and organic compounds.