We have studied that the influence of D.C. electric field on plant growth. This paper reports the effect of the D.C. electric field on seed germination and weight change. Raphanus sativus longipinnatus 〈daikon radish〉 and Arabidopsis thaliana 〈thale-cress〉 were tested. The results are following: (a)The application of D.C. electric field improves the seed germination rate in daikon radish and thale-cress. (b)The D.C. electric field increases the length and the weight of daikon radish. (c)The D.C. electric field encourages the consumption of substances which is stored in the seed of daikon radish.