A retractable pet house includes an enclosure frame and an optional top frame. The enclosure frame includes a plurality of poles, foldable connection rod units and locking joints. The upper end and the lower end of each pole are connected to the locking joints. The upper ends and the lower ends of both sides of the foldable connection rod unit are respectively pivoted to the locking joints. The top frame includes a central joint and a plurality of top rods. Each top rod has one end pivoted to the central joint and another end penetrating through the locking joint at the upper end of each pole. One end of each top rod is provided with a threaded hole for receiving a bolt to hold against the central joint. The inclination between the top frame and the central joint is variable by rotating the bolts.