Studies on the measurement of pigment contents and some characters of tomato fruits covered with red, green, blue or black cellophane bags, or black, red, white or transparent vinyl bags have been carried out at Department of Agriculture, Kyoto University and Shinshu University in 1958.<br> 1. The tomato plants were cultivated with the fruits covered with cellophane bags till Aug. 11. The fruits were then stored in the storage rooms maintained at 10°C and 20°C under an artificial light, and in the glasshouse of phytotron where the illumination by artificial light was added to the natural day light during the night, and the temperatures of 20°C and 30°C were maintained.<br> The content of pigments in the fruits depended upon the temperature stored, but not upon the difference of color of bags. The fruits stored at 20°C had a larger amount of pigments than the others, especially the fruits stored in glasshouse with artificial light showed the largest amount of pigments.<br> 2. The microscopical observation of chlomoplasts revealed many yellow granular masses in the flesh, of outer part of fruit and needle-shaped pink crystals of lycopene in the flesh of flower-end and core of fruit. Especially, the flesh of core has the largest amount of lycopene.<br> 3. During the cultivation of tomato plants, the maturity of fruits covered with vinyl bags of various colors was studied. The fruits covered with transparent vinyl bags required less number of days to mature. On the contrary, the fruits covered with black vinyl bags required more number of days to mature.<br> 4. From the results of measurement of pigment contents in the fruit 35, 60 and 55 days after anthesis, the fruit covered with white vinyl bag had the largest amounts of chlorophyll, carotene, lycopene and xanthophyll among the lots. On the contrary, the fruits covered with black vinyl bags had the smallest.<br> 5. All pigments contained in fruits were affected by the interception of light to the fruits. Carotene is the most affected, and lycopene is the least among the pigments. The light intensity enough for pigment development is considered to be about 30% of natural day light.<br> 6. All fruits covered with various vinyl bags were smaller in size and weight than the control. Especially, the fruits covered with black or transparent vinyl bags were smaller in size and damaged. While, the fruits covered with white bags were as good in their quality as the control. The control fruits showed much higher percentages of dry weight and higher pH values than the fruits treated. However, the fruits covered with white bags had higher sugar contents than the others.