To provide a frame structure serving as a rigid platform for a jogging stroller.

The frame structure comprises a frame member serving as a main structural body, a fork for receiving a mounting block assembly, a rear axle rotatably supporting a pair of wheels at its ends, a generally inverted- U-shaped handle member, a T-shaped interconnect mechanism, and a cam lever means pivotally supported against the rear axle. The interconnect mechanism and the cam lever means are in interactive engagement with each other so that the handle member can be relatively displaced to a first locking position where it is in a standing position during use and a second position in which the handle member makes pivotal movement to fold the frame assembly.