Frog shows similarity with human by having

Frog shows similarity with human by having hepatic portal vein. Hepatic portal system is found in all chordates. Hepatic portal vein is formed by the union of main veins, which drain venous blood from different parts of alimentary canal into the liver. 

Both frog and human are ureotelic.

Moist skin is the salient feature of frog for cutaneous respiration which doesn't seen in humans.

Frog exhibit indirect development by have tadpole in its life history. Humans show direct development.