本文針對兩岸三地（臺灣、大陸和香港）相互貿易的長期趨勢，利用「引力模型」以1980年到2000年間的貿易與相關經濟資料，來顯現兩岸三地的市場規模和貿易密集關係。實證結果如下：（1）1980年代初期，兩岸貿易量明顯偏低，但就兩岸三地而言，整體貿易區塊卻已顯著存在。這個結果顯示兩岸三地區域內的貿易量，顯著大於該地區經濟發展、市場規模以及地理關係所應有的平均水準。（2）1987年以前，香港在兩岸三地貿易的中介角色顯著存在。（3）1988年之後兩岸貿易則回復正常水準，1995年後兩岸貿易流量則呈現「異常地」活絡關係，亦反映1987年兩岸關係解凍之貿易效果。（4）兩岸三地內兩兩之間的雙邊貿易流量，自1995年起有超乎正常經濟發展的表現，突顯兩岸三地內彼此高度的貿易依存關係。（5）中國大陸的對外貿易初期效果有限，甚至只提升其與香港、臺灣（間接透過香港）間的貿易水準，對於世界其他各地的貿易則仍舊低於應有的水準。直到1988以後，大陸對外貿易效果方才「全球性」地顯現出來。

This paper is a first attempt at applying the gravity model to identify the evolution of a trading bloc among the Chinese circle, including Taiwan, Hong Kong, and Mainland China for the era after 1980. Special attention is paid on the role of the openness of Mainland China in shaping the Chinese circle's trade pattern. The major findings are as follows: (1) Firstly, there existed a trading bloc among the Chinese circle even in the early 1980s, and the bloc phenomenon has become more and more significant, especially in the 1990 and after. This result indicates to some extent that the trade flows within the Chinese circle are far above the normal level implied by their corresponding economic conditions and the geographical relationship. (2) The important role of Hong Kong as an agent in facilitating the trade within the region before 1987 is indirectly confirmed by our empirical findings, that is, the suppressed trade across the Strait in accompanied by above-normal trade intensity within the Chinese circle. (3) The trade flows between Taiwan and the Mianland China were once highly suppressed by the political situation but returned to its normal level after 1988 and exceeded normal in 1995 and after, indicating a growing mutual economic and trade dependency among the Chinese Three. (4) The opening-up policy of China announced in 1979 was indeed ineffective for the first few years, only improving to some extent its trade with Hong Kong and Taiwan. It was not until 1988 that Mainland China's open-policy became really global and effective.