Japan used to be an agricultural country, which traditional agricultural method has been organic farming. Health of farmers, environmental preservation and fertility existed at that time. The fact that the introduction of agrichemicals and fertilizers has rapidly expanded production output must be appreciated but many advantages of organic farming were lost. Organic farming primarily aims at environmental preservation and sustainable agriculture. In this report, lettuce (Lactuca saliva L.), KOMATSUNA (Brassica campestris L. var. komatsuna MATSUM) and spinach (Spinacia oleracea L.) were analyzed. For each vegetable, organically and conventionally grown agricultural products were obtained. We carried out the analysis of nutrient compositions and compared and examined the organically and conventionally grown agricultural products. In samples cultivated in multiple prefectures for this study, the difference caused by various cultural conditions could not be recognized in terms of moisture, ash content, minerals, vitamins and free amino acids contents. The data did not show any nutritional superiority of organically grown agricultural product.