Reducing high lost ratio of voluntary interpreters can save cost of recruiting and retraining for Taroko National Park¡¦s headquarters. The subjects of the study are the 114 voluntary interpreters in Taroko National Park. The methodologies applied here are, questionnaire and observation. The purpose of the study is to understand the relationship between the motivation of the voluntary interpreters and the job satisfaction of the voluntary interpreters to salve the problem of high lost ratio of voluntary interpreters. The findings of the study are as follows: 1.the motivation is mainly "self-growth". 2.the motivation will be changed with personal character and time passing by. 3. the factors influencing the voluntary interpreters¡¦ job satisfaction are "show loving care and support", "communication and co-operation", "responsibility and training". These factors will effect total satisfaction of voluntary interpreters. According to the findings of the study, proposes the headquarters of Taroko National Park how to provide relative courses, rich the content of work, and pay close attention for voluntary interpreters.