有些學生的數學成就表現不如其資賦的水準預期，我們稱之為資優低成就學生，或簡稱低成就學生。這些學生在學習階段是否會一直維持在相同的低成就類型？有無可能提升為成就型學生呢？本研究旨在驗證國中數學低成就學生，其類型、比率，以及不同成就類型之間轉換的動態情形；採用潛在成長模式，對數學低成就學生類型的變化，進行縱貫資料的潛在剖面分析。研究樣本為2,994～3,286位七、八、九年級學生，透過3年時間共進行五個時間點的測量。研究結果發現：一、普遍型的低成就學生，比率穩定的維持在50%左右；二、習得無助型低成就學生，隨著年級增長人數逐漸遞增，其數學成就在所有低成就類型中是最低的；三、焦慮型低成就學生，隨著年級增長人數逐漸減少，他們較常採用表現目標與自我設限策略來維護自我價值；四、完美主義型低成就學生，此類型學生比率最少，他們有較高的數學能力知覺，但卻比其他學生有更高的數學考試焦慮；五、臨界型低成就學生，隨著年級增長人數呈現遞減，他們較常使用自我調整策略幫助學習，是最有可能從低成就學生向上提升為成就型學生的一群。文末對數學低成就的議題與後續研究提出相關建議。 We call someone underachiever if he was born with gift, but performed worse than his own talent allowed. This study aimed at examining the changes in the types, the rate of math underachievers, and the dynamic transfer among various levels of achievement. It conducted a profile analysis about the changes in the types of math underachievers through potential growing mode and detailed data. The analysis involved 2,994-3,286 students from grades seven, eight and nine at five points in three years. The results are as follows: (1) The average underachievers remained stable at 50% or more; (2) The rate of underachievers increased as students moved to higher grades and they had the lowest math performance among all the types of underachievers; (3) The level of anxiety underachievers feel has decreased as they moved to higher grades; they tended to set goals when they study and maintain their self-value by limiting themselves; (4) The rate of perfectionism among underachievers is the lowest; they were intelligent in math in contrary but were more vulnerable to anxiety than other types of underachievers when they have a math test; (5) The number of borderline underachievers decreased dramatically as they moved to higher grades; they often use self-adjustment strategies to study. Suggestions for math underachievers from the author were included at the end of the paper.