本研究旨在探討國小六年級學生在理解統計圖所需的報讀、比較大小、計算、推論和摘要等五項能力的表現情形,特別是數學課程未進行教學的推論和摘要能力,並檢視高、低數學能力的學生在此兩項能力題目的理解表現是否有差異;統計圖理解層次分別為報讀資料、比較資料和解讀資料層次,本研究根據各理解層次的定義共細分出五項所需的能力,分別為屬於報讀資料層次的報讀能力、比較資料層次中的比較大小和計算兩項能力,以及解讀資料層次所需的推論和摘要兩項能力。為了解六年級學生在五項能力上的理解表現,本研究自行設計能夠反映五項能力內涵的統計圖理解層次測驗,並增加檢視學生是否能夠辨識統計圖的基本構成要素例如橫/縱軸的識圖題,即每個統計圖題組皆包含前述六種類型的題目,每人需回答七個題組,所採用的統計圖類型為學生在學校課程可學習到的長條圖、折線圖和圓形圖,統計圖主題包含社會課本單元中有採用統計圖的主題和日常生活中常見以統計圖呈現數據資料的議題。此外,採用學生的在校段考數學成績作為數學能力的依據指標。本研究發現,六年級學生在推論和摘要的表現是五項能力之中表現較弱的項目,其中,數學能力會影響學生在此兩項能力題目的表現,且學生在推論和摘要的表現有顯著差異。此外,影響摘要表現的因素包含學生的數學能力、統計圖主題內容及統計圖的複雜程度;根據本研究結果建議,在教學上,教師可提供目前學校課程未進行教學的推論和摘要能力之課程,藉由加強學生在此兩項能力的不足,可幫助學生具備從統計圖資料中獲取意義的能力。This study examined sixth grade students’ performance on the five abilities of graph comprehension, which include reading, comparison, calculation, reasoning and summarization. This study especially concerns with the ability of reasoning and summarization on mathematics curriculums that were not taught in class. In addition,this study also interested in whether mathematical ability will influence the performance on graph comprehension. Five abilities above-mentioned are subdivisions from three levels of graph comprehension (reading, comparing, andinterpreting data). The ability of reading is from the level of reading data. Comparison and calculation are from the level of comparing data, whereas reasoning andsummarization came from the level of interpreting data. Assessment test used in this study is structured based on three types of statistical graphics (i.e., bar chart, line chart and pie chart) and contained five types of questions, which are formulated in accordance to the definitions of five abilities. Every student has to answer seven questions. The basis of students’ mathematical ability is determined on students’monthly mathematical exams.Following results are found: Students’ performance on reasoning and summarization are significantly lower than the other three abilities. In addition, mathematical ability influenes the performance of these two abilities. From these results, one suggests that mathematics teachers should teach students more about reasoning and summarization. Because these two abilities help the students to derive meanings out of statistical graphics.