Abstract:In order to make clear the effect of transplant with supplementary water on seedling stage growth, yield and quality of sugar beet by paper cylinder seedling, ensure the suitable period for transplant, high yield and good quality of the sugar beet production. We researched and compared the structural characteristics of soil wetting between underground and traditional surface supplementary water, the impacts of supplementary water volumes to the development of root system and leaves in the seedling stage of sugar beet, and the effect of yield and quality of sugar beet under the conditions of transplant with supplementary water and two types of soils. The results showed that underground supplementary water has created a wetted soil ball wrapped the bottom of paper cylinder seedlings, it was useful to supply water for sugar beet seedlings and effectively to keep water in the field. With the supplementary water increasing, the lateral root numbers, taproot length, taproot diameter, fresh root weight, leaf numbers and leaf areas in seedling stage will be significantly increased. In cold and arid regions of North China, for the target of high survival rate and sound seedling, the suitable supplementary water amount was 150 to 200 ml·plant^-1 for the sandy chestnut soil, while it was suitable as 100 to 150 ml·plant^-1 for loam meadow chestnut soil, with a sugar beet root yield added 68.78% to 81.82% and sugar yield increased 65.57% to 81.82% compared with without supplementary water. Transplanting sugar beet with underground supplementary water was the key to increase the survival rate. So the suitable supplementary water was the basis for cultivating sound seedling and achieving high sugar beet yield. with proper water supply.