研究目的：本文回顧2歲前自閉症類疾患嬰幼兒篩檢工具。研究方法：本文從回溯性研究、前瞻性研究及眼球追蹤技術的研究方法，回顧2歲前自閉症類疾患嬰幼兒早期發展障礙。之後，本文依據當代自閉症類疾患篩檢工具兩層次的分類方式，簡介目前學界2歲前自閉症類疾患篩檢工具，及不同篩檢工具的敏感度與精確度。研究結果：2歲前自閉症類疾患嬰幼兒的早期發展障礙，主要出現在六方面，分別是：視覺／感官異常、動作能力落後、遊戲行為重複性、社會溝通障礙、語言能力落後以及認知能力落後。當代2歲前自閉症類疾患的篩檢工具，主要是層次一社區樣本的篩檢工具，層次二臨床樣本的篩檢工具比較少見。研究結論：不論層次一或層次二的自閉症類疾患早期篩檢工具，多數皆具備不錯的敏感度與精確度。台灣醫療場域，不同專業領域的工作人員，應該依據工作場域性質與篩檢目的，來選擇與使用自閉症類疾患早期篩檢工具。 Purpose: This article reviews screening tools for infants under 2 years old with autism spectrum disorders (ASD). Methods: Literature focusing on retrospective and prospective studies, and the studies of eye-tracking technique were reviewed for understanding the early signs in infants with ASD. Then, based on the findings of the literature, two levels of tools for infants with ASD were developed. We report the sensitivities and specificities and application of each screening tool for infants under 2 years old with ASD. Results: The previous studies suggested that infants under 2 years old with ASD showed early developmental signs in 6 domains, including visual/sensory abnormalities, delayed motor skills, repetitive play behavior, social communication impairment, and delayed language and cognitive abilities. Most screening tools for detecting ASD in infants under 2 years old are Level 1 tools, which are used to identify high risk infants with ASD from the general population. There exist few Level 2 screening tools, which are used to distinguish ASD from other developmental disorders. Conclusions: Both the Level 1 and Level 2 screening tools have good sensitivities and specificities. Suggestions are offered for selection and use of screening tools to detect ASD in infants under 2 in clinical settings in Taiwan.