Language development in preterm children is quite special. Behavioral studies found that preterm children were lagging behind their full term peers in areas such as vocabulary, syntax, and semantic verbal fluency. The effect of preterm birth on language development may last till early adulthood，and the degrees of such lags were influenced by biological and social factors. With the development of brain imaging, studies began to examine the brain development of premature children. Researchers have found group differences in white matter (WM) structures, subcortical gray matter (GM), and the cerebellum among preterm adolescents and their full term peers; yet the brain mechanism of language development in preterm children needs further researches to confirm. The paper describes the latest progress of behavior and neuron studies on preterm children's language development, thus to explore the law of language development and cognitive neuroscience mechanism in preterm children. Research suggests that behavior study and brain research should be combined to extend their advantages, thus to explore the mechanism of the language development of premature children, and to provide unique evidence of language acquirement of normal children.