People communicate each other in uttering any meaningful way with vocabulary. The knowledge of vocabulary and the ability to access that knowledge efficiently are recognized as important factors in reading and listening comprehension and speaking and writing fluency. Thus, vocabulary knowledge helps students with language comprehension. The purpose of this study has been to determine the measuring Khmer vocabulary size for each grade in basic education.Quantitative method was adopted to gather primary data from two newspapers issued for a weekand ninebooks of folktales. Descriptive statistics were then used to investigate the frequencies of words that were used in the one-week issue of the two daily newspapers and in a set of nice Khmer folktale story books.

Keywords : Basic Education, Vocabulary, Vocabulary Size, Word Frequency.