Fresh potato tubers of 13 different cultivars were analyzed for endogenous components and morphological traits in intact cells to study the relationship between traits of fresh tubers and the flavor of cooked (steamed) potato. Deliciousness composed of sweetness, potato taste and smoothness was significantly different between the cultivars; the tasting evaluations were reasonable when considering each tuber utilization, i.e. deliciousness of vegetable potato tended to be higher than that of the others, potato for processing and starch. The three main tasting traits were each related significantly, particularly potato taste had strong-negative correlation with sweetness and smoothness of tuber. The main tasting traits also had strong relationships to the starch content in cortex tissue of potato tubers. The starch content was significantly related negatively to potassium, phosphorus and cell size of cortex and they were related positively to smoothness of steamed tuber. The sweetness of steamed tuber was related negatively to the starch content, and the pH of the extract solution from cortex tissue was related significantly to both traits, sweetness and starch content. The potato taste of steamed tubers was related positively to starch content, but sweetness was significantly related negatively to potato taste by the physical traits of cortex tissue, pulp hardness and strength of cell wall binding. Thus, complicated flavor-linkages pivoting on starch through endogenous component and pH seemed to influence the deliciousness of steamed tubers, but traits that had no relation with starch content were also detected, such as silicon content. These results of this study may be useful for breeding potato cultivars with Japanese desirable flavor traits for use as vegetables.