Childhood period has a special importance; because how to pass this period and the way answering to the needs of child, make his belief and personality in adulthood. Proper education of children and use an appropriate method of educating for them has a wonderful effect on their personality in future. The Montessori Method of teaching has been one of the most common teaching methods in developed countries in the last decade. Montessori Method has different principles that have a positive effect on various developmental aspects of, including the cognitive, social and emotional aspects of children. Therefore, this study tries to show whether the Montessori Method affects some children's cognitive aspects. The aim of this article was the effectiveness of following Montessori Method of teaching and playing on pre-school children's temperament, attention and memory. The method of this study has been multivariate analysis of covariance. The research samples consisted of 18 girls and 16 boys. Sampling method was at random cluster sampling among pre-school's students who were taught in the traditional way and according to national education in 97-98. Instruments were the pre-school temperament and character inventory (ps-TCI), the Wechsler working memory scale (WMS), and continuous performance test (CPT). To test the hypotheses, statistical method including Kolmogorove-Smirnove test, Levene's test, and multivariate analysis of covariance were used. The findings revealed that the Montessori Method has a positive effect on temperament, attention and memory of Golha pre-school children. This research shows that when children are given tools, opportunities and time to express themselves as they wish, they show different talents and traits. The Montessori Method is a more appropriate method than the traditional and old education which is common in preschools and has a greater impact on different developmental aspects of children.