Objective: To early detect children with developmental language retardation and let them be timely intervention by studying the credibility of language ability evaluation of children aged 1-6 years by their parents and teachers. Methods: We performed a comparative analysis of 215 children's language ability between the evaluation of their parents and teachers and the language development quotient by Gesell Developmental Scales DQ (children's actual language skills). Results: (1) there were significant differences between the language ability evaluation by their parents and children's actual language skills in different age groups and different gender(P_{1-3 aged group}=0.002,P_{4-6 aged group}=0.033,P_{male group}=0.020,P_{female group}=0.047 ).In particular,there were significant differences about the parents of children's language ability evaluation results among the good level,bad level and the evaluation of the boy; (2) there were no significant differences between the language ability evaluation by their teachers and children's actual language skills in different age groups and different gender(P_{1-3 aged group}=0.803,P_{4-6 aged}=0.086,P_{male group}=0.565,P_{female group}=0.274); (3) the credibility of children's language ability evaluated by their parents and teachers were both less than 0.5 in different age groups and different gender, but the credibility of teachers' evaluation was higher than that of parents. Conclusion: The parents and teachers on children's language ability all have a high evaluation of the phenomenon, but the credibility of teachers than parents. So we should pay attention to the teacher report of the chlidren's language problem. And we need to improve the parents' and teachers' cognitive level of children's language ability, and use the professional assessment tools, in order to early detect children with developmental language retardation and give them early intervention.