A shaft coupling structure for a split type drive shaft comprises an internally splined female shaft and an externally splined male shaft coaxially received in the female shaft to establish a spline-connection. A play suppression member is interposed between the male and female shafts for suppressing play of the male shaft relative to the female shaft and vice versa. The play suppression member includes an elongate member extending in and along an axially extending groove defined between the male and female shafts. A hook portion possessed by the elongate member detachably fixes to one of the male and female shafts. The elongate member also has a biasing structure, which biases the male and female shafts in radially opposite directions.