Objective To compare the fracture resistance of the Co-Cr metal-ceramic crowns with four different marginal types. Methods A total of eighty Co-Cr metal-ceramic crowns were separated into four groups according to the four different marginal types. The first group was crowns with its metal framework extending to the facial margin of the shoulder. The second was crowns with its metal framework extending to the middle of the shoulder. The third was crowns with its metal framework ending with the axiogingival line angle of the shoulder. The last group was crowns with the metal framework extending to the 1 mm coronal to the axiogingival line angle of the shoulder. Each group had 20 specimens, which were kept in a bath of artificial saliva at 37 ℃ for 24 hours after cemented, followed by being subjected to Instron1342 testing machine. Each specimen was loaded at a speed of 1 mm/min, paralleled to the axis of the specimen until marginal fracture occurred. The loads at fracture were recorded. Results Group 2 obtained the largest fracture load(P＜0.05); Group 4 got the smallest(P＜0.05); In addition, there was no statistically significant difference between Group 1 and Group 3(P＞0.05). Conclusions The metal-ceramic crowns with the metal framework extending to the middle of the shoulder shows the largest fracture load; the metal-ceramic crowns with the metal framework extending to the 1 mm coronal to the axiogingival line angle of the shoulder demonstrate the smallest load; the fracture resistance of the Co-Cr metal-ceramic crowns with four different marginal types in this study can all satisfy the normal biting forces.