A T-shaped long absorption tube was applied to the atomic absorption spectrophotometric analysis of tin. The horizontal part of the absorption tube has a length of 50 cm and an internal diameter of 1.2cm. A sample is directry injected into an air-hydrogen flame by Jarrell-Ash Hetco atomizer burner, and light absorption of tin is measured at 2863 A. Employing the absorption tube, the linearity of calibration curve for tin was held in the range from 0.1 to 1.0 μg/ml, and the the limit of detection (1% absorption) was lowered to 0.02 μg/ml. The relative standard deviation was less than 3.4% at levels between 0.5 and 1.5 μg/ml. As a result of studies on interference, many substances were found to have a depressive effect on tin absorption, when present in more than a certain concentration. The date of analysis on canned fruit juices were in good agreement with those obtained by polarography.