This study is intended to elucidate gender differences of learning strategy use and learning achievement by Japanese EFL learners. Though much research has addressed the strategy area, few studies have addresed the learners' kinds of strategies and degrees of their use. Especially, gender differences are relatively ignored in research, although they are a socially important factor. Therefore, this research is intented to elucidate general tendencies according to gender and to derive suggestions for instruction from the aspect of Aptitude Interaction Theory. Data were obtained for 1,584 students from 38 high schools. Questions dealt with in this analysis were 36 items. A Otest and items from the STEP test measured learning achievement. Basic statistics are shown for fundamental study. Multi-group Confirmatory Factor Analysis using Structural Equation Modeling is used to examine the models shown in a preceding study, to compare models under several restrictions, and to estimate means of factors and correlations among factors. Data indicated that learning achievement and correlations among strategies and achievement can be interpreted at the same degree between male and female learners. However, only the factor mean (strategy use) differs remarkably: controlling for proficiency female learners use more strategies than male learners do. Pedagogical suggestions regarding this result are stated for classroom instruction in relation to Aptitude Interaction Theory.