It is the scholars unilateral conclusion that maca( Lepidium meyenii Walp.) is suitable for planting in the area more than 3 000 meters. In this study,we introduced the weighted grey situation decision theory to overcome the deficiency of the probability theory analysis method,the measure value on comprehensive effects was more complete and reasonable. The measure value of comprehensive effects results showed that,the comprehensive evaluation value of maca grown in more than 3 000 meters was higher than 0. ...