This study examined the influence of vocabulary skills and approaches to learning exhibited at age 3 on children s reading and mathematics skills, and language development at the 1st grade in elementary school. Analysis of KIEP(2008) showed that children who showed a higher level of vocabulary skills and approaches to learning at age 3 exhibited a higher teacher rated reading and mathematics skills at 1st grade. Indeed, these children with a higher level of vocabulary and approaches to learning at age 3 tend to demonstrate a larger language development despite such gap was reduced over time. Based on these findings the present study suggests a need for support before the start of school to compensate for a low level of school readiness by expanding the access of early education program.