本研究以臺灣229 家上市製造業公司為樣本，探討傳產業與資電業公司的國際化動機差異，對於國際化程度與績效關係的影響。有別於過去多數文獻，本研究以結構屬性的加權綜合指標來衡量公司國際化程度，以避免過去文獻用單一構面指標所造成的衡量問題。本文採用時間序列長期追蹤資料，利用一般最小平方法，控制出口密集度、產品多角化程度、研發與行銷密集度、負債比率、公司規模等變數，探討臺灣上市製造業公司的國際化程度對績效影響。研究發現樣本公司的海外子公司家數與海外子公司分佈國家數之平均值顯著低於歐美日等先進國家，顯示臺灣上市製造業公司處於國際化進程較早期階段，且海外子公司家數高於海外國家數，臺灣上市公司的國際化深度大於國際化廣度。另實證結果顯示傳產業公司的國際化程度與績效呈現ㄇ型關係，而資電業公司則呈現U 型關係，與過去文獻不符。本研究試圖提出可能原因來解釋這不一致結果，並提供實務的管理意涵與未來研究方向。

This study focuses on 229 listed Taiwanese manufacturing firms to explore the relationship between internationalization and firm performance by taking into account the motives behind the international activities of firms in both traditional industries and the electronics industry. We employ a composite weighted index to measure the degree of internationalization, which avoids the unidimensional measurement problem common in previous studies. Furthermore, panel data and the generalized least squares method are employed to explore the impact of internationalization on firm performance, to verify that differences between traditional industries and the electronics industry pertaining to export intensity, product diversification, research and development intensity, advertising intensity, debt ratio, and firm size are controlled for. We find that a number of overseas subsidiaries and a number of host countries are less than those in developed countries such as Europe, the U.S.A., and Japan, signifying that most Taiwan firms are currently in the early stages of internationalization. In addition, a number of overseas subsidiaries are more than a number of host countries, representing that the depth of internationalization is greater than the breadth of internationalization for Taiwanese manufacturing firms. Further, our results clearly show an inverted U-shaped relationship between internationalization and performance for firms in traditional industries, but show a U-shaped relationship for firms in the electronics industry, contrasting with prior results. We discuss potential reasons for these results, propose several implications for practitioners and also mention potential future research directions.