Abstract: The influence of nitrate reductase and soluble protein content on provenance growth of Quercus mongolica was investigated. The result shows that growth characteristics, nitrate reductase activity and soluble protein content have significant differences among the samples, the provenances of Suiyang possess the biggest value. Meanwhile, nitrate reductase activity and soluble protein content of different provenances vary with the seasons obviously. They have maximum values in June, which coincide with the fastest growth velocity. There is prominently positive correlation between the growth characteristics and the two physiological and biochemical factors,The provenances with stronger growth potential have higher nitrate reductase activity and more protein content. This investigation has provided fundamental information of predicting the growth state of Quercus mongolica.

Key words: Quercus mongolica, provenance, nitrate reductase, soluble protein