The present invention provide with a diaper sheath comprising: an inner and outer panel, each of said inner and outer panels having front and back portion connected by an intermediate portion, said front portion of the inner panel having an opening; and a front flap attached to said front portion of said inner panel, and said opening is covered by said front flap. The diaper of the present invention is much easier and convenient to adjust the insert from the opening at the front portion. With the flap at the front portion, parents can choose to use a biodegradable pad to insert in the flap and lay on the top of the inner panel.