Lasing performance of GaInP/AlInP lasers grown on misoriented GaAs substrates by gas source molecular beam epitaxy (GS-MBE) strongly depended on the substrate misorientation angle (SMA). In this paper, dependences of photoluminescence (PL) properties and carrier concentration of (AlxGa1-x)0.5In0.5P Crystals grown by GS-MBE, on SMA were systematically investigated. It turned out, through the PL measurements, that the Al-related non-radiative recombination in (AlxGa1-x)0.5In0.5P layers was reduced with increasing of SMA. On the other hand, the electrical activity of Be in p-type Al0.5In0.5P layers was enhanced together with increased SMA. These substrate misorientation effects in GS-MBE grown AlGaInP are discussed in connection with the improved lasing characteristics.