中文摘要：

通过建立一个两阶段混合寡占博弈模型，结合战略贸易理论考察了开放的经济环境里，国有大中型企业股份制改革对我国生产性补贴和进口关税水平以及社会福利的影响。研究发现，当其他条件不变时，最优关税水平随着国有化程度下降而降低，而最优生产性补贴水平随着国有化程度下降反而上升；国有企业完全私有化或完全国有化都有损我国社会总福利。

英文摘要：

This paper have built a two stage mixed oligopoly model to study how the large and medium-sized state-owned enterprises shareholding reform affect the China product subsidy , import tariff level and welfare within open economy environment. We found that when the other condition keep same, the optimal level of tariff decreases but the optimal level of subsidy increases with the degree of privatization coming down; neither privatization nor nationalization of state owned enterprise completely is harmful to the society welfare of our country.