1. Four new varieties of sweet potato pl3, p21, p30, and p46 were bred from 1947 to 1948, in Taipei. and were tested for adaptation at five localities in 1951. 2. Variety p30 appeared to be the highest in yield, and variety p46 appeared to be the best in quality, among all the other experimental varieties. 3. p13 and p21 are in no respect than the check so far as the useful characteristics are concerned. 4. It is therefore concluded that the substitution of p30 and p46 for native varieties through extension in northern part of Taiwan is rather promising.