The advances in researches on increasing trend of CO2 concentration in atmosphere and its impacts on plant growth and agricultural production in recent years is briefly reviewed. It is noticed that either so-called "direct effect"or "indirect impact",all have two implications, both positive and negative. Although, at present, there is a more or less general understanding of"negative larger positive", however, because of a lot of uncertainties in scientific theory and knowledges, how to synthetically estimate the impact of CO2 increase in atmosphere on plant growth and agricultural production is still a very important theme to be studied further in the future.