The purpose of this study was to investigate the relationship between learning strategies and metacognition with achievement scores of elementary school children. To achieve this purpose, 206 sixth grade children were sampled in Seoul-City, and the 'Questionnaire on the Learning Strategies and Metacognition' were administered to them. The collected data were analyzed by Pearson's Product Moment Correlation and Multiple Regression Analysis. The major findings of this study were as follows: Firstly, there appeared to be statistically significant correlations between learning strategies and achievement scores. The process of thinking variable of learning strategies were most significantly correlated with achievement scores (r=.251~.458, p<.001). The calculated R² indicated that the combined effects of process of thinking and affective domain on the achievement scores were about 21.5%. Secondly, there appeared to be statistically significant correlations between metacognition and achievement scores. The variables of controling and reviewing of metacognition were most significantly correlated with achievement scores (r=.278~.533, p<.001). The calculated R² indicated that the variables of controling and reviewing explained about 28.4% of the variance of achievement scores. Thirdly, there appeared to be statistically significant positive correlations between learning strategies and metacognition. The process of thinking variable of learning strategies were most significantly correlated with metacognition(r=.493~.662, p<.001). There appeared to be more statistically significant correlations between learning strategies and metacognition in the case of high achievers than that of low achievers. The results of this study shows that the development of learning strategies and metacognition could improve the achievement scores in school learning.