A convertible hand truck includes first and second truck frames coupled with each other through a pair of fixed members and a pair of pivoting members such that the second truck frame is turnable relative to the first truck frame among a folded position, a platform-cart position and a reclined-truck position. A stabilizing lever is pivotably connected with the second truck frame or the pivoting members to be engaged with or disengaged from the fixed members in response to the turning of the second truck frame. The second truck frame extends outwardly from the first truck frame in the reclined-truck position so as to expand and enlarge the carrying area of the hand truck for more loads.