Welfare and Institutions Code section 326.5 requires that in any dependency action after July 1, 2001, the juvenile court must appoint a guardian ad litem who is either an attorney or a court appointed special advocate to represent the interests of the child. The social worker or probation officer who files the petition may no longer act in this capacity. The statute has no retroactive application. Because the application of the statute is prospective only, the appellate court here did not determine whether the appointment of minor’s counsel in this case was sufficient in the absence of an order that independent counsel serve as both minor’s counsel and guardian ad litem.