The objectives of this research were to study the effects of the types of fruit and syrup and the can sizes and the addition of ascorbic acid on detinning and quality of canned fruits. Types of fruit were guava, red papaya, yellow papaya, banana, mixed fruit type A consisted of 44.4% pineapple, 34% yellow papaya, 20% nata decoco, 1.6% cherry and mixed fruit type B consisted of 46% pineapple, 15% yellow papaya, 20% guava, 4% banana. Types of syrup were sucrose syrup, syrup with passion fruit juice, pineapple juice, syrup with passion fruit and pineapple juice. Size of can were A1.5 and A10 and the addition of ascorbic acid to the level of 500-800 ppm. Were also studied. The samples were packed in plain cans and stored at room temperature (27-38℃) for 12 months. The contents of tin, ascorbic acid, total soluble solid, pH and acidity were monitored and the organoleptic property was evaluated for odor, color and flavor of syrup as well as color, flavor and texture of fruit pulp every 2 months interval. The results showed that the detinning in all the types of fruit and syrup, the different sizes of can and the addition of ascorbic acid were not significantly different (p > 0.05) . The tin content of canned fruits increased with storage time and was in the range of 116-202 ppm., lover than 250 ppm. Allowed by Thai Industrial Standard Institute. The minimum tin dissolving was found in banana canned in sucrose syrup and the maximum was in yellow papaya canned in sucrose syrup. There were no differences between odor, color and flavor of syrup and flavor of fruit pulps. The texture scores of fruit pulp of pineapple, guava and banana were slightly higher than red and yellow papaya. Dissolved tin was found to maintain the color of pineapple and yellow papaya but darken the color of guava, red papaya and banana. The panelists also found the samples to be acceptable through 12 months storage.