Objective To explore the natural characteristics of intelligence of the schoolage children with attention deficit hyperactivity disorder (ADHD).Methods 306 cases of untreated children with ADHD were divided into three groups (6~7 years old group;8~9 years old group;10~11 years old group) according to different ages.Children were in the ages from 6 to 11 years old,averaged (8.36±1.45) years old,256 males,50 females.Chinese Wechsler Intelligence Scale for children (CWISC) was used to test their intelligence and ANOVA analysis was used to analyse the intelligence results.Results Each result of the knowledge,vocabulary,comprehension,building blocks,puzzles,decoding between the three groups of children was statistically significant (P<0.05)，and in addition to decoding,each results of the high age group was all better than that of the low age group.The speech comprehension factor scales of the 8~9 years old group and the 10~11 years old group were all significantly better than that of the 6~7 years old group ;the perceptual organization factor scales that of the 10~11 years old age group was significantly better than that of the 6~7 age old group; the above differences were all statistically significant (P<0.05).The results of the other subtests,verbal scale,operating scale,the scale and the memory/attention factor between the three groups of children had no significant differences (P>0.05).Conclusions The intelligence development of untreated schoolage children with ADHD are abnormal,with the increase of age,in addition to the memory/attention factors other development abnormalities factors have gradually easing trend.