Abstract: Glycidyl chitosan (GC) with water solubility and organo solubility was first synthesized by reaction of glycidol with chitosan. In order to impart photo-triggered disassembly functionality to GC, 7-diethylamino-4-(hydroxymethyl) coumarin was succinylated and introduced to the side chains of GC. The structure of the resultant chitosan derivative (SCGC) was characterized by FT-IR and 1H-NMR. The photo-sensitivity of SCGC was studied by monitoring the changes in the diameter and Zeta potential of the micelles with UV irradiation. Results showed that SCGC could self-assemble into micelles, and critical aggregation concentration (CAC) of the micelles was 0.07 mg/mL. UV irradiation led to the increase in both the size and negative charges of the micelles surfaces.