Objective To study inductively coupled plasma atomic emission spectrometry(ICP-AES) used to determine blood boron(B),and to investigate the level of B in blood of children in Nanjing.Methods ICP-AES was applied to determine the level of B in the blood of 1032 healthy children and 1364 children patients after using 1mol/L HNO_(3) to treat whole blood.Results Precision of this method was 1.60%-4.31%,and recovery ratio was 93.3%-98.9%.The level of B in blood of the 1032 healthy children was(41.8?16.7)?g/L and that in blood of the 1464 patients was(25.1-58.5)?g/L(77%).Conclusion Precision and recovery ratio determined by the method are high,so it can be used as a reference method to detect the level of B in blood.And it preliminarily determines the reference levels of blood B of children in Nanjing as ranging from 25.1-58.5?g/L(except children below 1 year old).