過去以國際合資事業為焦點的研究已普遍受到重視，然而從雙方母公司的配適觀點及環境衝擊，探討國際合資事業不穩定性之研究則付之闕如。本研究旨在探討夥伴配適性及環境衝擊如何影響國際合資事業的不穩定性及績效，並提出四項研究假說。透過台灣與捷克之國營事業成立的國際合資事業為個案研究對象，本研究自雙方意圖合資至該合資事業成立以來之十年間(1995-2005)，依時間演化時程切割為33個事件階段，探討各事件階段序列之變化，以驗證研究假說。研究結果發現：(1)當國際合資事業夥伴間配適性越愈高時，其國際合資事業穩定性愈高；(2)當國際合資事業認知的環境衝擊程度越愈高時，則國際合資事業不穩定性愈高；(3)當國際合資事業夥伴問配適性越愈高時，其國際合資事業績效愈佳；以及(4)當國際合資事業不穩定性越愈高時，將導致合資事業績效不佳的狀況。最後提出相關建議供未來研究及管理實務運作參考。 The issue of IJVs has been widely noticed. Less attention, however, has been paid to the instability in IJVs. This paper aims at examining how partnership fit and environmental impact affect the instability in IJVs. Four hypotheses were proposed to address the correlations among constructs. We conducted an in-deth case study to investigat a focal IJV, which was joint-ventured by a Taiwanese state-owned company and a state-owned company in the Czech Republic. We identified 33 events happened in the IJV during a ten-year timeframe (1995-2005). The unit of analysis is each event. Statistical testes for 33 event-observations have revealed that four hypotheses were all supported, demonstrating that: (1) The higher the extent to which the partnership fit between two parent companies, the lower the instability in the IJV. (2) The higher the extent to which IJV perceived environmental impact, the higher the instability in the IJV. (3) The higher the extent to which the partnership fit between two parent companies, the better the performance of the IJV. (4) The higher the instability in the IJV, the worse the performance of the IJV. According to our findings, we discussed the implications and proposed suggestions for future research as well as for managerial practice. This study contributes a more complete exploration of instability in IJVs.