本研究係以2001年至2003年間宣告發行員工認股權憑證之上市(櫃)公司為研究對象，運用各種不同的績效衡量方法來探討宣告發行員工認股權憑證之長期營運及投資績效。 研究結果指出，台灣之上市(櫃)公司於宣告發行員工認股權憑證後，其營運績效呈現發行後第一年報酬率平均數最高，而後則有逐年衰退之趨勢。與相同產業平均值相比較，其獲利能力平均值統計顯著低於相同產業之平均值。而在資產運用效率則逐年成長，且顯著較同業為佳。 在長期投資績效方面，可發現採用不同之長期異常報酬衡量方法，會產生不同之平均異常報酬與檢定結果。在所有方法中，多數長期平均異常報酬是負值，而結果中亦存在一些不顯著異於零之正的長期平均異常報酬。因此，若從統計假設檢定的角度來看，我們似乎仍沒有一致且充份的證據證明：樣本公司於發行員工認股權後之股票報酬存在長期異常之現象。 最後，在敏感性分析實證結果發現，長期營運績效方面，得知不論是上市或上櫃公司或是在那一年度宣告發行員工認股權證，樣本公司在宣告發行員工認股權後，都沒有顯著提升其獲利能力，且仍顯著低於同產業之公司。長期投資績效方面，仍無法得到一致且充份的證據證明：樣本公司於發行員工認股權後之股票報酬存在長期異常之現象。 The long run operating and investment performance of issue the employee stock option of common stock listed on TSE and the OTC market in Taiwan was studied, the period was from 2001 to 2003. Different performance measurement methods were discussed in the study. The result of study is pointed out, after the company of Taiwan declares that issues the employee stock option evidence, the operation performance revealed that had the highest av-erage rate of returns in the first year after issuing, later there was trend of declining. Com-pared with the same industry, examine the apparent level which is lower than the same in-dustry of definite value in its earning capacity. In addition the efficiency of assets keep growing, and apparent better than same trade. We found if the long-term investment performance adopt different long-term abnor-mal return method , will produce different abnormal return and examine result. In all meth-ods, the value of most long-term abnormal return is negative, and also have positively ab-normal return which is not apparent. So examine from statistical hypothesis, we don’t have identical and sufficient evidence to assert: The long-term abnormal phenomenon of the stock return after issuing the employee stock option of sample company is existent. Finally, the result of the sensitivity analysis discovers that after the sample company no matter listed or went to the TSE and OTC companies in Taiwan or which year the company issued the employee stock option that could not improve its earning capacity apparently and still lower than the same industry of long-term operation performance. Long-term investment performance is still unable to obtain identical and sufficient evidence to assert: The long-term abnormal phenomenon of the stock return after issuing the employee stock option of sample company is existent.