GaAs/AlGaAs quantum wires grown by molecular beam epitaxy on a V-groove patterned substrate was described. The cross section of scan electron microscopy (SEM) image shows that crescent-type quantum wire were formed at the V groove bottom, which is a triangle of about 60nm in width and 14nm in height. Two peaks at 793.7nm and 799.5nm of photoluminescence spectrum at 87K verified the existence of quantum wires. Theoretical calculation gives 8meV blue shift, which is proved to be casued by lateral confinement compared with quantum well of the same width.