A simple, environmental and economical capillary electrophoresis method has been developed for the analysis of four model proteins by employing a photoactive and non-toxic diazoresin (DR), D-Glucurone modification of the inner surface of fused-silica capillary. DR/D-Glucurone coated capillary not only effectively eliminated the wall adsorption of proteins, but also showed good stability and repeatability. Instead of using the moisture sensitive and toxic silane coupling agent, the application of photosensitive DR may provide a flexible and environmentally friendly strategy to prepare novel covalently coated capillaries. Thus, DR/D-Glucurone coated capillary has great potential in capillary electrochromatography and may provide a new method for biological compounds separation.