Abstract: There are many problems in the peanut production at present time, such as lodging, blossom without bearing fruit, bearing too much fruit resulted in not-plump fruit . In order to solve the problems, the experiments were carried out to study the effects of MET on the physiological and agronomical characteristics and yield of peanut. We hoped to find out the best PP333 density treatment and the best application period. The result showed that: the leaves became thicker, and the contents of chlorophyll, soluble sugarcame and Protein were increased under the MET application treatment. The MET could effectively restrain the growth of the main stem, while it could support the branch development and pegging. As the result, the lodging-resistance of peanut, the rate of pegging、beaying fruit and the plump extent were increased.