To study the clinical efficacy of Compound Radix Arnebiae Oil in treating children with irritant diaper dermatitis. Methods: Compound Radix Arnebiae Oil was used in treating 45 cases of children with irritant diaper dermatitis to observe the cure effect before and after the treatment and the changes of symptoms. Results: The cure effect was up to 89%. The difference of scores of skin lesion area, skin color, ulcer, exudate, degree of cry and noise before and after the medication were statistically significant (P<0.05). Conclusion: Compound Radix Arnebiae Oil in treating irritant diaper dermatitis in children is clinically effective, worthy of application.