本文旨在探討存在網路外部性下，最適兩部定價授權策略：「從量加固定權利金」與「從價加固定權利金」。研究結果顯示隨網路外部性由弱至強，授權廠商的最適契約呈現「逐步轉換」：初期僅採用從量或從價授權金，進而轉為採用兩部定價契約，最終在網路外部性高度顯著時，轉為僅收取固定授權金。此外，本文得到從價兩部定價不差於從量兩部定價，且當網路外部性極強時，從價和從量兩部定價利潤均等，具利潤等價性。儘管授權可能造成消費者剩餘下降，但社會福利必定提升；且隨著網路外部性的增強，授權契約的逐步轉換將有助於消費者剩餘的提升。

This research investigates the optimal two-part tariff licensing (a fixed fee with a per-unit or an ad valorem royalty) in markets with network externalities. The core finding is a gradual transition in the optimal contract as network effects intensify. Firms initially prefer a royalty-only contract, then shift to a two-part tariff, and ultimately adopt a pure fixed-fee model when network externalities become very strong. When network externalities are extremely strong, both per-unit and ad valorem two-part tariffs yield equivalent profits. Regarding welfare, licensing always enhances social welfare, although it may reduce consumer surplus. Lastly, the gradual transition of licensing contracts, driven by stronger network effects, contributes to an increase in consumer surplus.