Though it is not easy for those who study dendrology to memorize all the scientific names of trees, the names remaines in their memory can facilitate the understanding of foreign technical books. The scientific name of a tree indicates characteristics of shape, color, and other aspects of the tree and by analyzing the name we can see common element found in other scientific names of trees. It is helpful to those who want to memorize and study the scientific names of trees if they understand their etymology. The preseut study is the seconds report of the investigation which aims at examining the etymology of the scientific names of native and foreign trees growing in Korea and their original names not only at the habitat but in Japan, China, England, Germany, and France. While the first report, which was made known in Theses Vol. 9. (The City College of Seoul 1975), is the examination of the scientific names of trees belonging to Gymnospermae, the present report is that of scientific names of trees belonging to Piperales: 2 families, 2 genera and 2 species; and trees belonging to Salicales: 1 family, 3 genera, 44 species, 16 varieties, and 3 forms. As the etymology of the scientific names of trees is made clear, this study will help those who want memorize the scientific names and study foreign technical books and it is also useful for international interchange of trees. The classification is depended chiefly on Dendrology by Prof. Lee Tchang-bok and "Plant Resources of Korea" shown in Biblography No. 10; the native names of trees on Jumoku Daizusetsu by Dr. Uehara; and etymology on A source-Book of Biological Names and Terms by E.C. Jager. In the column of etymology of the scientific names for genera, species, varieties and forms, Gr. stands for Greek, L. for Latin, NL. for New Latin, and genit. for genitive.