Purple bronze KxMo6O17 single crystals are successfully grown by electrolytic reduction method from the melts of K2CO3 and MoO3.The detailed process of the preparation is reported.The structure of the single crystals are investigated with x-ray diffraction and Transmission electron microscope.The results show that the crystals have large sizes and high qualities.The unit cell parameters are:a=b=0.5540nm,c=1.3508nm，and the crystal structure is refined to be trigonal with space group P3.The temperature dependence of resistance reveals that the compounds undergo Peierls phase transition at 112K.