Contents of chromium, zinc and copper in the blood (or serum), liver and kidney of diabetic rats induced by streptozotocin were determined for three weeks by graphite stove and flame atom absorption spectrophotometry to study the changes in trace elements in diabetics. Results showed liver chromium level increased significantly and kidney chromium level lowered significantly in diabetic rats, as compared with normal ones. Zinc and copper in liver and kidney and serum copper also increased to various extent during three-week observation period. No changes in chromium, zinc and copper levels in blood (or serum), liver and kidney, with the course of the disease, were observed. But, contents of trace elements in rats correlated with their blood sugar levels closely, and chromium, zinc and copper contents in the liver correlated with those in the kidney directly, and with chromium content in the kidney inversely. Therefore, improvement of blood sugar level in diabetic rats may, to a certain extent, improve the disturbance of trace elements in the body.