The low luminescence of serum is tested with the low luminescences detection system. In the experiment the low luminescence of serum of the hyperglycemia, hyperlipoidemia, and normal man are tested respectively, and the laws of serum radiation intensity with variation of blood sugar and triglyceride concentration are studied. And the image of the low luminescence of serum is analyzed quantitatively with self-programmed software. The experimental result shows that the serum radiation intensity increase synchronously with blood sugar concentration linearly. The gray threshold of triglyceride luminescence image also increases with triglyceride concentration, but it is not obviously as the former one. So the blood sugar concentration can be estimated by the serum luminescence intensity, and it is effective. It provides experimental foundation for the medical diagnose.