The influence of Ti-Ni shape memory alloy post for a post hole was investigated.Prefabricated straight-slit type posts(Smooth surface, 1.6mm diameter)caused stress because of lack of homogeneous contact.The stress on the post hole caused by a new trial post(Theraded surface, 1.5mm diameter)above the transformation point(martensite structure austenite structure)was two times as large as that below that point.At a temperature of 35℃, the shape memory alloy's post made of martensite structure caused less stress on the shape memory alloy's post made of austenite structure.Stress of new trial posts made of a martensite structure for the post hole was approximately 1.5MPa.The thickness of a post had no influence on the thickness of the cement line;the average thickness was 13.4μm.The thickness of the cement line did not change with the change of the structure of shape memory alloy.A new trial post(No.1-4)was always cemented rightly in the center of the post hole.