Aim: To evaluate their prognosis, the damage by melamine on children's kidney and other organs, and its influence on the children's development, was investigated. Methods: Nine hundred and sixty-two Chinese children were divided into three groups: group A, 265 children diagnosed with melamine-associated urolithiasis; group B, 197 children with a history of melamine-contaminated milk powder consumption but without urolithiasis; and group C, 500 healthy children. They were examined at 0, 1, 3, 6 and 12 months. The factors influencing the prognosis were investigated. The stone discharge was monitored by ultrasonography. Overt renal and liver damage and underlying renal injury markers were analyzed. Results: The stone discharge rates 1, 3, 6 and 12 months after the diagnoses were 52.5%, 67.2%, 88.3% and 95.5%, respectively. Stone size was a stable influencing factor for the stone discharge rate. Additionally, the values of the potential renal injury markers in children with stones already discharged is equivalent to normal children. Conclusion: This 12 month follow up of early renal injury markers indicated that the damage to the kidney is temporary with no persistent negative outcomes being found till now. Additionally, the gross development of the children seemed not yet jeopardized by melamine. Longer-term follow up will be conducted.