A golf club shaft (10) having a weight not less than 30 g nor more than 60 g. The golf club shaft (10) includes a bias layer (B1) composed of a prepreg whose reinforcing fibers have an orientation angle of not less than ±10° nor more than 80° to an axis of the golf club shaft (10) and a straight layers (A1 through A6) each composed of a prepreg whose reinforcing fibers have an orientation angle within 0°±10° to the axis of the golf club shaft (10). At least one partial reinforcing hoop layer whose reinforcing fibers have an orientation angle of within 90°±10° to the axis of the golf club shaft (10) is disposed in only an important reinforcing region in a range from a point (P) spaced at 15% of a full length (L) of the golf club shaft (10) from a grip-side butt (12) thereof to a point (Q) spaced at 45% of the full length (L) of the golf club shaft (10) from the grip-side butt (12) thereof.