臺灣證期局宣佈於2018年1月1日開始適用IFRS 9，根據新準則重新檢視對企業交易是否有尚未考慮周全之處。為確保財務資料的準確，有必要嚴謹的對待員工股票選擇權的定價工作，這對於新準則下公司財務管理的優化具有重大意義。
考慮到員工股票選擇權在條款設定上有別於傳統選擇權的特殊之處，本文提出的員工股票選擇權評價模型在傳統選擇權評價模型的基礎上進行改進。模型考慮了利率期限結構、公司在不同時間點向投資者部分發放可行權比例、投資者可能提前行權、稀釋效應，以及投資者在行權之前會涉及到錨定效應等等。
本文以日月光公司2018年發行之員工股票選擇權為例進行實證分析，分別使用本文提出之定價模型進行定價，以及按照美國財務會計準則委員會在徵求意見稿中提議的方式使用Black-Scholes模型進行定價。然後，論文比較兩模型計算結果上的差異及其背後的原因。此外,本文通過對員工股票選擇權評價模型中影響選擇權定價的關鍵因素，進行敏感度分析，並觀測本文所提出的模型是否符合選擇權價格與關鍵定價因素之間應有的關係，以此來證明本文模型在選擇權評價的邏輯關係上的正確性。

The Taiwan Securities and exchange bureau announced that IFRS 9 will be applied on January 1, 2018, and it will review whether there is any incomprehensibility in enterprise transactions according to the new standards. In order to ensure the accuracy of financial data, it is necessary to treat the pricing work of employee stock option seriously, which is of great significance for the optimization of financial management of the company under the new standards.
Considering that the employee stock option is different from the traditional option in terms, the evaluation model of employee stock option proposed in this paper is improved on the basis of the traditional option evaluation model. The model takes into account the term structure of interest rate, the proportion of exercisable shares issued by companies to investors at different time points, the possibility of early exercise and dilution effect of investors, as well as the anchoring effect of investors before exercise, etc.
In this paper, we take the employee stock option issued by ASE Group in 2018 as an example for empirical analysis. We use the pricing model proposed in this paper and the Black-Scholes model according to the way proposed by the FASB in the draft to price ESO respectively. Then, the paper compares the differences between the two models and the reasons behind them. In addition, this paper analyzes the sensitivity of the key factors influencing the option pricing in the employee stock option evaluation model, and observes whether the model proposed in this paper conforms to the proper relationship between the option price and the key pricing factors, so as to prove the correctness of the model in the logical relationship of option pricing.

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