近年來國際間電信市場上，由於電信自由化風潮的影響，促進電信市場競爭和保障消費者用戶的相關規定和政策陸續制定出現。號碼可攜服務隨著電信市場的逐漸成熟與開放新進業者的加入等，其實施的迫切性和需求性則越來越重要。另一方面，韓國和台灣兩國皆有相同的共識，先後推動實施所謂的行動電話號碼可攜 (Mobile Number Portability)服務，讓民眾在更換不同行動電話業者服務時，仍能夠保有使用原號碼之權利和便利性。 本論文的研究目的：(一)是想以較台灣先實施行動電話號碼可攜服務的韓國為主要的研究比較個案國家，瞭解韓國電信主管機關的政策制定過程、探討行動通信市場現況、消費者用戶的需求與行動通信業者的回應與市場策略；(二)再輔以參考其他已實施國家經驗中的成功與失敗的因素，與台灣的相關政策、業者策略和消費者用戶的態度等，做綜合性的對照和分析比較，提供台灣在未來實施過程中的建議。 主要的研究方法為文獻分析法與深度訪談法。並且針對「政府相關部門的政策制定」、「消費者用戶的需求」和「行動通信業者之因應策略」，以及「政策實施後所造成的影響」四大問題面向進行探討和分析。 研究分析結果整理發現，韓國和台灣在先後實施行動電話號碼可攜服務之後，的確增加消費者用戶選擇業者的權利，和促進行動通信市場上各家業者的競爭和發展。行動通信業者為了鞏固既有用戶基礎和吸引別家用戶上門，無不提供更多樣的費率包裝和增加服務內容。 研究建議台灣目前已實施之行動電話號碼可攜服務，應該：(一)縮短申請攜碼移轉作業的時程；(二) 加強維護消費者用戶的權益措施；(三) 健全新舊業者之公平競爭機制。 / In recent years, because of the influence from telecommunication liberalization in the international telecommunication market, there are many policies of improving competition in the telecommunication market and protecting consumers are made one after another. Along with that the telecommunication market becomes gradually mature and new operators join competition, the implementation of the number portability service is getting more and more important. On the other hand, South Korea and Taiwan both implemented the so-called "Mobile Number Portability Service", allowing mobile subscribers to switch service operators while retaining the same mobile phone number. The purpose of this research is: (1) to try to make a comparative study of Mobile Number Portability Service between Taiwan and South Korea. (2) And it will also give some useful suggestions to improve the implementation of Mobile Number Portability Service in Taiwan, by learning experiences from other countries which have implemented Mobile Number Portability Service. Using literature review method and deep-in interview method, this research discusses and analyzes four major research questions: "the government’s policies", "the subscribers’ demands", "the operators’ strategies" and "the influence from implementing Mobility Number Portability Service". This research finds out that, after implementation of Mobile Number Portability Service in South Korea and Taiwan, it indeed provides more freedom for subscribers to select service operators and stimulates the competition and development in the telecommunication market. Besides, every service operator provides more tariff packages to consolidate old subscribers and attracts new subscribers form other service operators. This research suggests the implementation of Mobile Number Portability Service in Taiwan should: (1) reduce the time of application for Mobile Number Portability Service; (2) strengthen the measure of maintaining subscribers’ interests; (3) create a fair competition mechanism.