Yttrium isopropoxide was prepared directly by the reaction between yttrium and isopropyl alcohol using mercuric chloride and iodine as catalyst. Yield is above 83%. This method possesses the merits of easy operational approach, high product purity, high reaction rate and high production rate. Compared with the previous reported results, the period needed was shortened by 19h and the yield increased by 8%. The period needed for preparation is about 5 hours. These results are better than the present report. The dehydrolysis method of isopropyl alcohol and the composition of catalyst were presented.