兒童雖然只經歷短暫的人生，但生活壓力的累積已使其行為及學業的適應上產 生困擾。而在眾多的因素中，社會支持乃是最受研究者青睞的壓力保護因子之一。 本研究旨在以實驗室模擬壓力情境，並採生理反應為壓力指標，以探究兒童在面對壓力 時，社會支持對兒童壓力下生理反應之影響，究竟扮演直接效果亦或緩衛效果？ 本研究採 2 （作業難度） *3 （社會支持）二因子混合重複量數實驗設計。作業難度 代表兒童在生活中碰到壓力源的大小，共分為難、易兩個層次。社會支持計分為以問題解決 為中心、以情緒支持為中心及無支持等三個層次。 本研究以桃園縣龍潭國小四年級的學生為取樣對象，隨機抽取 106 名四年級學童分成 三組。各組由不同教師扮演其中一種社會支持的型態；每一組受試均需接受容易及困難的兩 種作業。以生理回饋系統持續監控並記錄受試者在實驗過程中的心跳及膚電反應；個別訪談 則是在實驗完成後進行之。 研究結果顯示：（ 1 ）瑞文氏標準圖形推理測驗可為一有效的實驗室壓力源。（ 2 ） 社會支持對不同強度壓力情境的兒童，在生理反應（膚電）上產生緩衛效果。即在高壓力下 ，無論是問題解決性或情緒性的社會支持對均具舒緩兒童壓力有幫助，但在低壓力狀態下， 社會支持，對兒童壓力舒緩無所助益。（ 3 ）由訪談結果發現：兒童對情境的「認知」會 影響到其對壓力的生理反應。 Children exposed to an accumulation of stressful life events within a relatively short time span are at risk for behavioral and academic difficulties. Among environmental and personal factors, social support received most concerns as a protective factor under stress. The purpose of study aims to investigate the role of social support plays buffering effect or main effect when children are under stress. The "2(task difficulty) × 3(social support) two-factor repeated measure" is employed in this expe iment. Task difficulty represents the degree of stressors children encounter in daily life. The two degrees of task difficulty are easy ones and hard ones; the three levels of social support are problem-solving focused, emotional focused, and no support. One hundred and six 4-grade student volunteers are obtained from Long-Taing elementary school. Subjects are divided into three groups, and the teacher in each group plays one type of social support role. Next, every child will be required to do two tasks of different difficulty degrees in standard progressive matrices. In order to make the arrangement of task sequence in a counterbalanced way, half of the students will do an easy task first, followed by a hard one; the other half students will do the tasks in a reverse succession. The computerized biofeedback system will monitor and record by every one second. The interview is followed after experiment. The results of study are as follow: (1) the standard progressive matrices is a valid stressor in this exp iment. (2) social support on children's physiologic reactivity (skin conductance) also yield buffering effect model. That is to say, social support is good for health because it does reduce activity under high level of stress but not under low level of stress. (3) from interview，children's cognition influences the physiologic reactivity during tasks.