We fabricated a photonic crystal (PC) laser having a circular defect cavity and a line defect output waveguide based on a heterostructure consisting of a slab layer with quantum dots and an AlO x cladding layer. The photonic crystal laser was excited by a 785 nm laser diode. Samples with different parameters have similar threshold values of about 25 µm Roomtemperature continuous-wave lasing operation at 1.3 µm range is confirmed by observing the spectrum of output light from the line defect waveguide. The wavelengths of the lasing modes show the dependence on the radius of circular resonator and the radius of air holes, which indicate that the lasing mode is the whispering-gallery mode. These results show the feasibility of realizing PC lasers using AlO x cladding layers.