Cutaneous respiration is a type of respiration where the exchange of air takes place through skin or outer integument of a frog. 

Frog has an extensive folds of skin that helps it in the increased rate of respiration. The pulmonary arteries is divided into two part, one goes into the lungs while the others goes to the skin. This makes the skin of a frog highly vascular. Due to their thin skin they live in a moist environment and secrete mucous from the skin to avoid desiccation. 

This helps him to remain underwater for a long period of time, while getting to keep their blood oxygenated.