Objective To investigate the relationship between source memory and item memory in children,adult and the elderly Chinese,to test the hypothesis that neuronal substrate of source memory includes frontal lobe,and that source memory and item memory were dissociated in child and the elderly.Methods A neuropsyehological battery was established to measure the performance of item memory and source memory.Child,adult and the health elderly Chinese(40 cases in each group, respectively)were enrolled.The performance of child and the elderly Chinese were compared with that of the adults,and were also analyzed among the groups to check the dissociation between the performance of item and source memory.Results Compared with the adults,the source memory in children(I value:0.87?0.08 vs.0.73?0.13,P＜0.01)were impaired,but not found in item memory(Pr value:0.73?0.14 vs.0.74?0.11,P＞0.05).The elderly Chinese was impaired in both item(Pr value:0.66?0.15,P＜0.05)in source memory(I value:0.68?0.13,P＜0.01).Double dissociation between item and source memory was found in the child and the elderly.Conclusions The evidence of double dissociation between item and source memory within child and the elderly supports the dual-process model of source and item memory.These findings also support that frontal lobe involves in source memory,the indicators of source memory damage is early behavior marker for mild cognitive impairment or early Alzheimer disease.