This study was designed to evaluate the correlationship between radiologic classifications of cysts in oral region and glycosaminoglycan analysis of cystic fluids using cellulose acetate electrophoresis. The materials for this study consisted of 37 cases-8 periapical cysts, 10 dentigerous cysts, 10 primordial cysts, 2 residual cysts, 3 incisive canal cysts, 2 post-operative maxillary cysts, 1 mucocele on maxillary sinus, & 1 unicystic ameloblastoma-diagnosed as cystic lesions radiologically. The obtained results were as follows: 1. At the stepwise discriminant analysis, four variables-low mobility material, heparin, hyaluronic acid, & dermatan sulfate-were used to define diagnostic model for the odotogenic cyst. The model produced a sensitivity of 100% and a specificity of 85%. 2. The intensities of heparin and chondroitin-4-sulfate were greater in dentigerous cyst than periapical cyst(p<0.05). The intensity of chondroitin-4-sulfate was greater in primordial cyst than in periapical cyst(p<0.05). 3. It showed no statistically significant difference in glycosaminoglycan of the cystic fluids between dentigerous cyst and primordial cyst(p>0.05). 4. On the fluids of the cysts originated from maxillary sinus, there were especially high intensities of heparin and dermatan sulfate, and low intensity of chondroitin-4-sulfate. 5. On the fluids of unicystic ameloblastoma, there were high intensity of dermatan sulfate and low intenity of chondroitin-4-sulfate.