本研究主要在於探討當公司營運現金流量水準不同時，企業研發支出（R&D）對營運績效影響之門檻效果。樣本選定2001年至2007年間台灣上市公司之電子資訊產業作為研究對象，實證模型則採用Hansen（1999）之門檻自我迴歸模型進行實證分析。實證結果顯示企業研發支出與公司營運績效間，存在上下不對稱之非線性關係，當公司營運現金流量高於門檻值時，企業研發支出對營運績效呈現正向顯著結果；但當營運現金流量低於門檻值時，兩者則呈現負向關聯。據此可知，當經理人為追求短期績效而進行研發投資活動時，對當期績效而言，乃其有反噬利潤的現象。故實證結果建議企業經理人在進行相關研發活動時，應考量公司營運現金流量的多寡，方能提昇公司整體的價值。

This study aim at examining the threshold effect between research and development (R&D) expenditures and company performance at different firm's operating cash flow. The sample selects the electronic listed firms in Taiwan from 2001 to 2007. Empirical model uses the panel threshold autoregressive model by Hansen (1999). Our results show that there is significantly asymmetric non-linear relationship between R&D and operating performance. In other words, R&D present a positive significantly effects on firm's profit while operating cash flow is high than the specific threshold value. Additionally, R&D is found to be negative and statistically significant relationship if operating cash flow is smaller than the threshold value. It, therefore, it will erode company profitability when firm's manager raise R&D expenditures for increasing the profit in short term. Consequently, our overall results suggest that manager need to incorporate the level of operating cash flow into the R&D active to advancing firm value.