An inner-focus type zoom lens system used for a camera module having an image sensor and using an LC lens is provided. The inner-focus type zoom lens system includes an objective lens group, a condensing lens group, at least one moving lens group, and an LC lens. The objective lens group is located most closely to an object side and fixed, and the condensing lens group is located most closely to an image side and fixed. The moving lens group is located between the objective lens group and the condensing lens group and moved for zooming. The LC lens includes an inner space filled with an LC material whose refractive index and abbe number change according to an applied voltage. The LC lens compensates for an image plane using the changes of the refractive index and the abbe number of the LC material when the zooming is performed by the moving of the moving lens.