The association between blood lead of children and Intelligent Quotient(I.Q) was investigated in a sample of 100 boys and girls aged $6sim8$ years from one primary school within an industrial area of Pusan. The trained undergraduates in school of public health administered an 1.0. test one by one. Parents answered a questionnaire on demographic, perinatal and socioeconomic variables. Atomic Absorbtion Spectrophotometer was used to determine blood lead levels. The geometric mean of blood lead value was $7.99{mu}g/dl$. In total children, there was no significant relationship between blood lead level and I.Q. But in the children who were born of gestational age of less than 38 weeks, children with higher levels of blood lead performed more poorly on I.Q test with correlation coefficient from -0.68 to -0.71. But, the children who were born of gestational age of 38 weeks and more were same as total children. These results suggest that exposure to low levels of lead in the children who were born premature probably may result in impaired intelligent development. But, We think that more profound study should be performed with sufficient numbers of subjects.