A zoom lens including a first lens group, a second lens group, a third lens group, and a fourth lens group with positive, negative, positive, and positive refractive powers respectively arranged in sequence from an object side to an image side is provided. The first lens group includes a first lens and a second lens. The second lens group includes a third lens, a fourth lens, and a fifth lens. The third lens group includes a sixth lens. The fourth lens group includes a seventh lens, an eighth lens, and a ninth lens. The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, and the ninth lens respectively having negative, positive, negative, negative, positive, positive, positive, negative, and positive refractive powers are arranged in sequence from the object side to the image side.