Although previously published studies have revealed a significant relationship of reading amount, vocabulary, and reading comprehension skills, few studies have been published on this topic in which the participants were Japanese elementary school children, especially first and second graders.  In the present study, first to sixth graders (N=992) in Japanese elementary schools completed a survey that included 6 indices of reading amount, including the number of books borrowed from the school’s library and a test of recognition of titles.  The results were as follows: (a) overall, all measures of how much the children had read were positively related to their scores on vocabulary and reading comprehension, and (b) no strong positive correlation was found among the measures of reading amount.  The present results may serve as a foundation for future development of language education in Japan, and for further methodological examination of measures of reading amount.