The exterior color of the round-spotted viper is similar to that of the general mountain viper, but the round-spotted viper is stronger and closer to olive color. There are irregular black spots. The head is triangular, the head is clearly distinguished from the neck, and the snout is short, wide and round. The small scales on the back of the head are ribbed, the nostrils are large, and they are located at the upper end of the snout. The back is brownish-gray, with 3 longitudinal large round spots, the center of each round spot is purple or dark brown, the outer periphery is black, the outermost has irregular black-brown markings, the abdomen is gray-white, scattered with thick dark brown spots .

In addition, the round-spotted viper is about 1.5 meters long and weighs more than 1.5 kilograms , The body is sturdy, the tail is short, and the middle part of the body is round and thick, and the proportion to the neck is almost one-third.