The object of this study was to evaluate the effects of climatic elements on potato yield and create a model for estimating the potato yield. We used 35 yield data of Sumi variety produced in mulching cultivation from 17 regions over 11 years. According to the results, some climatic elements showed significant level of correlation coefficient with marketable yield of potato. Totally 22 items of climatic elements appeared to be significant. Especially precipitation for 20 days after planting (Prec_1 & 2), relative humidity during 11~20 days after planting (RH_2), precipitation for 20 days before harvest (Prec_9 & 10), sunshine hours during 50~41 days before harvest (SH_6) and 20 days before harvest (SH_9 & 10), and days of rain during 10 days before harvest (DR_10) were highly significant in quadratic regression analysis. 22 items of predicted yield (Yi=aXi 2 +bXi+c) were induced from the 22 items of climatic elements (step 1). The correlations between the predicted yields and marketable yield were stepwised using SPSS, statistical program, and we selected a model (step 2), in which 4 items of independent variables (Yi) were used. Subsequently the Yi were replaced with the equation in step 1, aXi 2 +bXi+c. Finally we derived the model to predict the marketable yield of potato as below. Y = -336×DR_10 2 + 854×DR_10 – 0.422×Prec_9 2 + 43.3×Prec_9 – 0.0414×RH_2 2 + 46.2×RH_2 – 0.0102×Prec_2 2 – 7.00×Prec_2 – 10039