Abstract: The main contradiction change of economic development is not the same concept as the change of social main contradiction. The former is the main component of the latter and can be regarded as the main contradiction and change of the society which is embodied in the economy. At present, the main contradiction of Chinas economic development is the imbalance of structural supply and demand, the root of which is the lack of effective supply, which is the logical premise and theoretical basis of the structural reform of the supply side. Chinas economic development has entered a new normal. The main contradiction of economic development has been transformed from the imbalance in supply and demand to the structural imbalance between supply and demand. Its contradictory nature is transformed from total scale to structural one. The main contradiction is not the demand side, but the supplier side.

Key words: the main contradiction of economic development , effective supply , structural reform on the supply side

摘要： 经济发展主要矛盾变化与社会主要矛盾变化不是同一概念，前者是后者的主要组成部分，可以看作是专门体现在经济方面的社会主要矛盾变化。当前我国经济发展主要矛盾是结构性供需失衡，根源在于“有效供给”不足，这是供给侧结构性改革的逻辑前提和理论根据。我国经济发展进入新常态，经济发展主要矛盾已经由总量上的供求不平衡转化为结构性供需失衡，矛盾性质由总量性规模性转化为结构性的，矛盾的主要方面不在需求方，而在供给方。

关键词: 经济发展主要矛盾 , 有效供给 , 供给侧结构性改革