Abstract: Three experiments were carried out to investigate the development of written and spoken language in primary school children of the second grade. The results indicated:1. In the period of the second grade, the quantity and other characteristics of the children's vocabulary in written and spoken language do not show much difference. The children can use the written language to express their ideas mastered orally.2. Training the oral expressions of children through group discussion, helps to raise the quality and quantity of their written language.3. Children of the second grade are not capable of correcting their written language, but this ability is beginning to develop at this age.Based on these results, the author proposed some suggestions to improve the quality of children's composition.

Key words: NULL