中國經濟發展快速的情況下，人民對於汽車的需求也一直再提高，在基礎建設尚未追上汽車數量增加之下，道路擁擠與環境汙染成為了許多城市必須面對的問題。北京市政府於2010年12月23日實施汽車限購政策，希望透過此政策降低汽車增加的速度。另一方面，中國將發展汽車自主品牌作為重要政策之一，希望藉由外資的技術讓自主品牌的汽車打入國際。因此本文將使用差中差法進行估計，研究北京市在汽車限購政策之後，政策對於自主品牌銷售的影響。 研究中所使用的資料為中國「中國車輛登記管理所」之中的「全中國登錄各月新增車輛」，加上「易車網」的汽車特性資料整理而成。以北京市的自主品牌車系作為實驗組，非自主品牌車系作為對照組進行多次估計，其中包括加入時間趨勢及將極端樣本去除等。研究結果皆顯示，在汽車限購政策後，確實對於自主品牌汽車銷售有下降的影響，最後也加入了穩定性檢驗，證明自主品牌的銷售下降是否與政策有關。最後結果亦與預期相同，證實北京市的汽車限購政策對於自主品牌的銷售有負向的效果。 / With the rapid economic growth in China, people’s demand for automobiles has risen continuously during the past decades. Furthermore, because the infrastructure in China failed to sustain the increase in the quantity of automobiles, traffic congestion and environmental pollution are the problems many cities have to be confronted with. Therefore, Beijing government adopted Automobile Purchase Limit Policy in Dec. 23, 2010, hoping that through the policy it can decrease the growth rate of automobiles. On top of that, developing self-owned Brand for automobiles in China is its primary policy, China government hoped to take advantage of foreign technology to make its self-owned Brand step into the international market. Consequently, this article uses Difference-in-Difference method to analyze how the sales of self-owned brand automobiles would be affected after the Automobile Purchase Limit Policy was enacted. Data used in this article is from Monthly Increase in Registered Vehicles Across China, which is from Vehicle Registration and Managemet Bureau of Chian, and from Yiche Network. Setting the self-owned brand mobiles in Beijing city as an experimental group and non-self-owned brand mobiles as a control group, we are to estimate many times. We try to take time series effect into account and eliminate outlier samples. The result shows that after the Automobile Purchase Limit Policy, the sales of self-owned brand automobiles significantly decrease. Finally, we add stability test to observe whether the decrease in the sales of self-owned brand automobiles is related to the policy or not. The result reveals that the Automobile Purchase Limit Policy in Beijing has a negative impact on the sales of self-owned brand automobiles.