我國自民國84年起實施全民健康保險，因採論量計酬的支付制度，造成醫療支出大幅增加。為抑制醫療費用成長，於民國91年7月全面實施總額支付制度，預先固定健保年度總額，雖有效控制醫療支出，但醫院因財務受到箝制而壓縮人事成本，醫護人員存在過勞、工時過長等問題，當醫院所面對的市場競爭程度越高的情況下，是否使得人事成本更加壓縮，進而影響醫師轉科或執業決策，為本文主要研究目的。 本研究係採用國家衛生研究院發行之全民健保資料庫，由於僅住診檔提供完整資料，故本文選取有開刀紀錄的醫師進行分析。市場競爭程度衡量上以半徑方圓法劃分各醫院的市場範圍，並以醫師執刀數作為賀芬達指數(HHI)的計算單位，研究期間為民國87年至民國99年，再控制醫院權屬、醫院層級、醫師性別、醫師年齡及人口密度等變項後，以邏輯斯回歸模型(Logistic Regression)探討市場競爭對醫師職業規劃之影響。研究結果顯示，賀芬達指數愈低，代表市場競爭程度愈高，醫師處於越競爭的市場時，越會選擇轉換科別或不執刀。 With the implementation of the National Health Insurance (NHI) in July 1995, the accessibility of seeking medical treatment was increased.However Fee-For Service resulting in a substantial increase in health expenditures. To control the growth of medical costs, the implementation of the global budget system in 2002. The global budget system fixed annual medical expenditures in advance. Although effective control medical expenditures, the hospital due to financial restrictions and cut down costs. Medical personnel had long working problem. The purpose of the present study is the higher degree of market competition when the hospital faced the situation, whether making personnel costs down more compressed thereby affecting the switch departments or practice of physicians In this study we use National Health Insurance Research Database, National Health Research Institutes. Because only hospitalization files provide complete information, therefore we have chosen surgery physician records were analyzed. The degree of market competition use Radius Circle Around Approach to divide range of market. Herfindahl-Hirschman index is use the number of physicians to operations. The study period is during 1997 to 2011, control variables are hospital tenure, the hospital hierarchy, physician gender , age and population density others.We use Logistic regression to test the affect between Market Competition and physician career. The results show that Herfindahl-Hirschman Index with a physician switch or choose not to surgery influence negatively. Herfindahl-Hirschman Index lower the value, representative of the higher degree of market competition, the physician easier to conversion divisions or choose not to surgery.