A soft zoom lens system includes an axially expandable or shrinkable holding portion, a supporting portion, a first lens and a second lens. This holding portion has an inner space, a first end and a second end. The supporting portion is made by a soft material. The first lens is disposed between the first end and the supporting portion. The second lens is disposed between the second end and the supporting portion. When this holding portion is applied by predetermined electricity, it will expand or to shrink axially. So, the curvatures of the first lens and the second lens will be changed. The zooming is performed. The invention's structure is simple. The adjusting of focal length is easy. The production is easy with low cost.