A baby stroller comprising: a base and a suspension unit connected to the base, the suspension unit having a movable rod which is movably connected to the suspension unit, and a support frame connected to a distal end of the movable rod, a distance between the support frame and the base being adjusted by movement of the movable rod, wherein the movable rod is rotatable relative to the suspension unit, a positioning seat mounted to the suspension unit and having at least one restriction portion, the support frame has at least one control rod which is located corresponding to the at least one restriction portion, the at least one control rod is connected to the at least one restriction portion when the at least one control rod is located at a locked position, the at least one control rod is disconnected from the at least one restriction portion 41) when the at least one control rod is located at an unlocked position, the support frame is pivotable when the movable rod is pivoted, characterized in that the support frame has a tube which has at least one passage, at least one slide is located in the at least one passage and connected to the at least one control rod, the at least one slide has a stepped face, at least one movable block is inserted into the at least one passage and located substantially perpendicular to the at least one control rod, the at least one movable block has a rail which is an inclined surface and located corresponding to the stepped face of the at least one slide, the at least one slide is moved up and down when stepped face of the at least one slide is moved along the rail. a base and a suspension unit connected to the base, the suspension unit having a movable rod which is movably connected to the suspension unit, and a support frame connected to a distal end of the movable rod, a distance between the support frame and the base being adjusted by movement of the movable rod, wherein the movable rod is rotatable relative to the suspension unit, a positioning seat mounted to the suspension unit and having at least one restriction portion, the support frame has at least one control rod which is located corresponding to the at least one restriction portion, the at least one control rod is connected to the at least one restriction portion when the at least one control rod is located at a locked position, the at least one control rod is disconnected from the at least one restriction portion 41) when the at least one control rod is located at an unlocked position, the support frame is pivotable when the movable rod is pivoted, characterized in that the support frame has a tube which has at least one passage, at least one slide is located in the at least one passage and connected to the at least one control rod, the at least one slide has a stepped face, at least one movable block is inserted into the at least one passage and located substantially perpendicular to the at least one control rod, the at least one movable block has a rail which is an inclined surface and located corresponding to the stepped face of the at least one slide, the at least one slide is moved up and down when stepped face of the at least one slide is moved along the rail.