The present study was conducted to describe and examine the development of children's reading and writing behaviors and their awareness of differences between oral and written language. and to investigate the effects of nondirective teaching method of reading in which adults regularly read story books for the children and encouraged them to reread or respond at their own level of reading ability. The hypotheses of this study were as follows : Hypothesis 1 : Children of age 2 through 6 would show developmental progression in reading-writing behavior as age increased. Hypothesis 2 : The nondirective teaching method of reading would have facilitative effects on development of reading-writing behaviors. Hypothesis 3 : Home written-language environment would influence children's development of reading and writing. Hypothesis 4 : The ability to discriminate oral and written language and to use the language which fit to the context would increase as age increased. Hypothesis 5 : The nondirective teaching method of reading would have facilitative effects on the development of discrimination of oral-written language. Hypothesis 6 : There would be positive correlations among reading and writing abilities and discriminations of oral and written language. To test these hypotheses. 92 children. from age 2 through 6. were sampled from homes. day-cares. and kindergartens in Seoul and randomly assigned to either nondirective teaching or control group. The children in nondirective teaching method of reading were read story books for 10 to 30 minutes everyday. Thirty five reading sessions were administered using more than 150 kinds of story books (about 30 for each age). The pre and the post test following 35 reading sessions were taken to compare the nondirective teaching group with the control group. To examine the development of oral-written language discrimination. children's told(oral context). dictated. hand-written,, and re-read (from their own hand-writing) stories(writteen context) were collected after story book reading and block construction. The results of this study support the hypothesis 1 and 2. and Indicate that children's reading behaviors develop from preconventional reading such as labelling, paraphrasing. making-up stories governed by pictures. to conventional reading, that writing behaviors develop from scribbling to conventional writing, and that the nondirective teaching of reading has facilitative effects on the development. The hypothesis 3 were partially supported since home literacy environment and interactive effects with age and teaching. The hypotheses 4, 5, 6 were also partially supported. The Children's productions signalled differences between told (oral language) and dictated. handwritten. and re-read stories (written language) but the individual differences, not the age, played an important role in discrimination ability. Even very young children who have not yet acquired proficient oral language can use written language in the written context. The nondirective teaching method have no main effects but interaction effects with age. Positive correlations among reading-writing abilities and decontextualization abilites were found.