This study was to estimate the number of Chinese characters school students know from Grade 1 to 9.  There were 2,842 students randomly selected from 19 schools in Taiwan.  A 5,021 high-frequency character set was divided into 17 levels in terms of difficulty.  A character list was then sampled from the 17 divided levels.  Results showed that the average number of characters a student knew from Grade 1 to 9 increased from 700 up to 3,700.  They also indicated that there were significant grade and gender effects.  Students gained in number of Chinese characters at a rapid rate during the period of Grade 1 to 5.  Based on the results, some suggestions for curriculum standards and the basic literacy education were proposed.