This paper reports the influence of D.C. electric field on plant growth. We used the white radish sprout as the sample. The seeds of white radish sprout were grown under two circumstances; one is under electric fields, and the other is without electric fields. We have confirmed the following things: 1. The application of D.C. electric field improves the germination rate. 2. The D.C. electric field increases the length and the weight of the sample. 3. However, after removal of water by vacuum treatment, the weight of the sample subjected to the D.C. electric fields turns to be lower than that of the sample not subjected. This result suggests that the D.C. electric field accelerates the growth of the plant; it does not increase the real plant weight, but just improves the stem elongation by water absorption, and encourages the consumption of substances stored in the seed. The D.C. electric field probably activates the work of phytohormone called Gibberellin, which is reported to induce germination, and to encourage the stem elongation by absorbing water.