在服務傳遞時，第一線服務人員是否展現出正向情緒表達與角色外顧客服務行為，使顧客享受服務，影響甚鉅。本研究將建構在服務業組織環境下組織支持導入工作績效的歷程，目的在於檢視組織支持能否正向影響服務人員的正向情緒表達與角色外顧客服務行為，透過服務人員所展現的這兩種行為能否進而提升工作績效的可能性。本研究以餐飲服務業中美食餐廳為研究對象，並採問卷調查方式蒐集基層員工、主管與顧客三類資料，以降低相同來源偏差。為考量變項間因果關係，問卷在三段時間發放，其中第一時間段（T1）進行員工自評其組織支持；第二期間段（T2）則是研究大專生現場觀察服務人員的正向情緒表達，又服務中顧客評量服務人員的角色外顧客服務行為；第三時間段（T3）直線主管則評員工的工作績效。分析結果顯示，員工知覺組織支持連結到正向情緒表達與角色外顧客服務行為，這兩種行為分別進而提高工作績效；正向情緒表達與角色外顧客服務行為皆具有部分中介效果。

When service delivery occurred, it is the immense impact for firstline service employee whether to show positive emotional expression and extra-role customer service behavior, motivating customers enjoy the service. The present study in service industry context examined whether organizational support positively relates to positive emotional expression and extra-role customer service behavior, respectively, and also examined whether both of these behaviors from service contact employees enhance their task performance. Data were collected from 217 employees, 23 managers and 486 customers at restaurants in food service industry. To enhance the clarity of the causal relationship among variables of the present study, questionnaires were distributed at three time points. In this study, constructs with different sources (e.g., employee rated their perceived organizational support in T1; employee’s positive emotional expression is rated by research assistant’s observation, and customers rated extra-role customer service behavior in T2; while supervisors rated their employees’ task performance) in order to reduce the possibility of same source bias were measured. The results showed that perceived organizational support positively linked to positive emotional expression and extrarole customer service behavior, both behaviors thereby improving employees’ task performance; positive emotional expression and extrarole customer service behavior have the partial mediating effects.