This study was conducted to test the following hypotheses : (Ⅰ) There are significant differences in causal attributions for success and failure depended upon cognitive developmental status - concrete and formal operational stages ; (Ⅱ) There are significant differences in the achievements of academic science depended upon cognitive developmental status. In the preliminary experiment, 59 junior high school girls in Seoul were interviewed to find attributional elements in three specific task situations. On the basis of this result, attributional elements consisted of ' ability', 'tast difficulty', and 'luck' for congnitive task; and 'ability', 'steady efforts', and 'luck' for two academic achievement tasks. The questionnaire measuring attributions was to be answered about each element based on a 10 point Likert-type scale. Interjudge reliabilities of cognitive developmental status experiments were composed of the Piagetian balance test and pendulum test were rho = .85 (p < .001) rho = .72 (p < .001). Reliabilities of science achievement test composed of primary and higher mental process items were all α = .74. The subjects for the main experiment were 123 junior high school girls. The result indicated that between the concrete operational thinkers and the formal operational ones attributions on the cognitive task and the science achievement task were partially significant but attributions on the cumulative academic achievement task were not statistically significantly different. It showed significant differences between two cognitive developmental stage groups in the science achievement test and school cumulative science achievement. Consequently, hypothesis (Ⅰ) was partially supported and hypothesis (Ⅱ) was confirmed. Additional analyses were as follows: (1) The eifference of attributions in the science achievement task situation depended upon science achievement levels ; (2) The difference of attributions in the cumulative academic achievement task situation depended upon cumulative achievement levels ; (3) The cognitive developmental status of subjects . Findings from these analyses coincided with the expectations of previous Literatures. Possible explanations and suggestions for following studies were discussed.