Abstract: The purpose of the present invention is to provide a yoke and shaft joint structure with which joint strength of a metal junction of a yoke and shaft that configure a steering device can be obtained with a very simple structure and a very small size, and a joining method therefor. The joint structure is obtained from a yoke (A) having a cylindrical section, a shaft (3) having a joint-side shaft end (31) that is joined by metal to the cylindrical section (2), and a synthetic resin covering (4) that covers the entire circumference of the junctions site of the cylindrical section (2) of the yoke (A) and the joint-side shaft end (31) of the shaft (3). A portion of the synthetic resin covering (4) is filled and solidified in yoke through holes (23) formed in the cylindrical section (2) and shaft through holes (33) formed in the joint-side shaft end (31) of the shaft (3).