Objective To compare the shaping ability and the influence on apical foramen among hand ProTaper, stainless steel K-files and rotary ProTaper in preparing different curved root canal. Methods Forty simulated resin root canal blocks were randomly divided into four groups and prepared by hand ProTaper, stainless steel K-file and rotary ProTaper, respectively. Of them, 12 blocks in group A, B, C consist of six 20° curved root canals and six 30° curved root canals each group. The curvature of the other 4 blocks in group D was less than 5°. Taking photos of the models to the root canal orthotopically and apical foramen using digital camera before and after instrumentation. Finally, the transportation of root canal and the size of apical foramen were analyzed using special image software Auto-CAD. Results The transportation of center in group B was the highest than that in group A and group C（P
