The three-year research on stem-apex meristem culture and fast reproduction technology of sweet potato selected out MS+6-BA 1.0mg/L+NAA 0.1～0.2mg/L＋3%sucrose＋agar6.0g/L and 26～30℃ respectively as the preferential medium and appropriate temperature range. And the average devirus rate was 83.7% based on the semiological diagnostic and plant indicator identification. The reproduction coefficient for the fast propagation with cut test-tube plantlets was 5 n, the reproduction speed increased at a geometric progression and large-scale seedlings could be multiplied in a short time. The virus-free seedlings transplanted in fields reached a yield increase of 37.8%.