外資和外貿是促進北京經濟增長的兩大因素，而且外資與外貿互動發展現象日趨明顯。為了探索外資增長對外貿增長的促進作用，本文分析了從 1998 年到 2006 年的北京市外資與外貿資料，發現北京市外貿總額與實際利用外資規模具有同步增長關係，進而提出一個假設：北京外商直接投資規模的增長和投資結構的變化是支撐其外貿規模增長和結構轉變的一個重要力量。 為了驗證假設的真偽，本文開展三項工作：一是深入北京市各區縣收集外資企業出口資料，分析結果表明：外資出口在北京市及區縣出口中發揮著重要作用。二是北京市外資總額與出口總額、外資總額與進出口總額的關係進行了回歸分析，分析表明外國直接投資作為解釋北京出口、進出口的重要原因比較適當；三是依據回歸模型，對 2007 年外貿規模進行了計量預測， 2007 年年底實際資料將會進一步檢驗上述假設。定量分析表明：假設成立。 在此基礎上，本文對未來影響北京外資發展進而影響外貿的重大因素進行了定性剖析，指明了外貿促進中應當重視的外資促進問題。最終得到一個基本結論：跨國公司在北京進出口貿易中扮演著重要角色。 隨著中國區域平衡發展戰略的實施，在深圳特區、浦東新區之後，濱海新區的設立加速環渤海經濟圈的興起，京津雙龍共舞。北京作為京津經濟新幹線的龍頭，近年投資規模壯大，結構調整優化，高科技和服務業投資增長迅速，這極大地推動了北京外貿規模的增長和進出口結構的升級。一些對外國直接投資具有重大影響進而影響區域進出口的因素值得連續關注和深入研究。

FDI and trade are the two factors to promote the economic growth of Beijing . In order to explore the role of FDI in the foreign trade growth, the paper analyzes 1998-2006 data of FDI and foreign trade in Beijing , and it is found that Beijing 's foreign trade volume increases in parallel with the actual use of FDI. So, a hypothesis is put forward: Beijing 's FDI is a major force supporting the growth and the structural changes of foreign trade in Beijing . To verify the authenticity of assumptions, this paper carries out three tasks: First, foreign export data from Beijing and its districts are collected and analysed. The results show: the foreign export plays an important role Beijing and its districts' export. Second ， applying a regression analysis on relation of Beijing FDI an export total it is shown: FDI can offer an explanation why Beijing export and important are always increasing. Third, based on the regression model a forecast is made for 2007, which will be tested by the actual data in the end of 2007. On this basis, the paper takes a qualitative analysis on significant factors which have some impact on the future growth of Beijing 's FDI and in turn affect foreign trade. The results show: it is important to promote FDI for Beijing 's foreign trade. Finally a basic conclusion is here: multinational companies play important roles in regional import and export trade. The research results have positive significance for the foreign investment and trade work.