本研究旨在探討國民中學校長的專業發展及其相關因素，主要的研究目的是了解國民中學校長專業發展影響因素、對專業發展重要性的看法和參與多樣化專業發展意願之間的關係，並提出我國國民中學校長專業發展改進與進一步研究的建議。 為達成研究的目的，本研究根據文獻探討結果，提出研究架構與假設，編製調查工具「國民中學校長專業發展情形調查問卷」進行預試，回收的有效問卷共134份，經由因素、信度分析刪題和文字潤飾後，問卷修正為「中學校長專業發展情形調查問卷」，隨後實施正式調查，共回收有效樣本問卷398份進行統計分析，開放填答的題項也加以歸類析述。 有效樣本經以描述統計、t考驗、單因子變異數分析、皮爾森積差相關、多 元迴歸分析等方法進行分析比較，獲得下列結論： 一、國中校長愈重視專業發展政策和目標，參與多樣化專業發展型態和主題的意願愈高。 二、適度的工作壓力對校長專業發展產生積極影響，但家庭壓力則有消極影響。 三、國中校長感受到的政府專業發展作為的積極性不足。 四、在專業認同度方面，年輕校長不如資深校長。在同儕之間的專業互動頻率方面，鄉鎮學校、資深、高齡和即將退休的校長，較城市學校、資淺、年輕和非近期退休的校長為低。 五、女性國中校長比男性國中校長具有較強的學習自信、較多的校長互動和較高的專業發展參與意願。 六、校長專業發展在不同年齡和年資上，呈現互有優勢的現象，即將退休的校長則有較多不利的情形。 七、心理問題的紓解和改善，是國中校長重視的專業發展目標。 八、校長對具有威脅性、會帶來強制措施的專業發展政策，會給予較低的重要性評比。 九、國中校長樂於參與多樣化的專業發展型態，非正式的參訪、研討、聽講，比體制化的調查、研究、發表，更受校長青睞。 十、國中校長樂於參與多樣化的專業發展主題，尤其是學校經營實務和當前教育改革有關的主題，但參與電腦科技、興趣培養和生活知能的意願較低。 根據研究結論，研究者對教育行政機關提出：設置專責單位或人員，規劃研擬積極的校長專業發展政策；透過法令、文件、方案或計劃，清楚而明確地表述國中校長專業發展目標等建議。對國中校長提出：廣泛成立校長同儕組織，積極轉化校長組織的功能，加強校長同儕互動學習；協力增進校長專業問題的發聲，求取校長與教師專業發展機會的平衡等建議。對未來的研究，提出：分析國中校長同儕組織的成立及其在專業發展的功能、問題和影響；進行各國國家層級或地方層級的校長專業發展制度比較等建議。 / Professional Development of Junior High School Principals and Its Factors The purpose of this research is to understand the relationship between influential factors of professional development, views of professional development importance, and the will of participating in diverse professional development of junior high school principals, and to propose suggestions of improvement and further study. With the questionnaires and statistic analysis of 398 junior high school principals, the conclusions are as follows: 1. There is a positive relationship between the views of professional development importance and the will of professional development of junior high school principals. 2. Working pressure and family pressure cause respectively positive and negative influences on professional development of principals. 3. The government lacks the active policy to assist the professional development of junior high school principals. 4. The professional identity of young principals is lower than senior principals. Besides, the principals who are in town schools, senior, aged, and going to retire lack professional interaction with colleagues. 5. Female junior high school principals have the professional development advantages of confidence of learning ability, interaction with other principals, and higher participative will. 6. There are different advantages of professional development of principals for different ages and seniority, while the principals who are going to retire have more disadvantages. 7. The relief and improvement of the mental problems of principals are the professional development purpose which junior high school principals put emphasis on. 8. Principals have the view of lower importance of threatening professional development policy. 9. Junior high school principals are willing to participate in diverse professional development. Principals prefer the unofficial learning development models rather than the official ones. 10. Junior high school principals are willing to participate in diverse themes of professional development, especially the related themes of school management practice and current educational reform, while they are not so willing to participate in computer technology, interest cultivation, and living skills. According to the conclusions of this research, the researcher proposes some suggestions to education authorities, junior high school principals, and future research directions.