基本能力評估是香港特區政府面對21 世紀全球化、知識為本的社會和經濟等變化與挑戰的一個重要因應策略。本文旨在介紹香港基本能力評估（BCA）的設計原則和實施情況。「學會學習的評估」是基本能力評估設計的核心思想。基本能力評估包含基本能力評估之學生評估，和全港性系統評估兩個組成部分。前者是為在第一至第三學習階段的中、英、數三科所提供的低風險、標準參照、自發性的校內在線評估。目的是促進校內教學效能。後者是一個由政府中央管理、全港學校參與的保密測試。目的是為政府提供本港學生在這三科達到基本水平的數據，以作為教育決策的準則。本文簡介基本能力評估的設計、評改方法、報告方式、標準制定、和公眾的接受程度等議題。

This article presents an overview of assessment reform in terms of the Basic Competency Assessment (BCA) in Hong Kong. The BCA has two components, namely, the BCA Student Assessment and the Territory-wide System Assessment (TSA). Items used in the TSA are put back into the BCA Student Assessment item bank the following year, so essentially the two components have identical item type and level. The former is designed to provide Hong Kong schools a strong platform of assessment for learning and is to be used by teachers for their daily teaching and the later is to give schools and the government system level data on student performance at Key Stages One to Three. The BCA has received very favourable support from schools and teachers. The development of the BCA is grounded on recent research findings that the feedback is one of the most important factor contributing to learning. The BCA system aims to provide quality feedback in order to help teachers to better align teaching with students’ levels and to support schools and the government in formulating evidence based policymaking. This paper gives the theoretical underpinning of the BCA, a description of its components, designs, and reporting features.