The purpose of this study was to investigate that the character of language development by children and the
influence that aggressive and prosocial behavior on focusing two years old. The target on this study 208 two years old
children. This study was to check socio-demographic items to find differ depend on sex and monthly age by two years
old children’s mother. And the character of language development was to assess their mother and the aggressive and
prosocial behavior to assess their teacher. So this study collected 208 two years old children data for statistics analysis
to use SPSS 20.0. At the result this study follow that; At first, language development of two years old children was
not to relate by sex, but to relate by monthly age. Second, ‘express language’ were found to negatively influence their
‘language aggression’ as subscale for aggression, but ‘receptive language’ were not found to significantly influence
aggression of two years old children. Third, ‘express language’ were found to positively influence prosical behavior for
all subscale, but ‘receptive language’ were not found to significantly influence for statistic. This study results were to
suggestive that language development of two years old was to influence their aggressive and prosocial behavior. So it
seems to contribute to use basic information for pervasive development on childhood.