The present invention provides a lens driving device and a magnet holder thereof. The magnet holder comprises a support plate, and one of the three following units is formed at the part of the support plate opposite to a linear spring along the direction from a front side surface to a Z axis direction back side: (1) at least two steps, wherein a through hole through which the linear spring passes is formed at a last step close to the Z axis direction back side, (2) at least two grooves with gradually narrowed inner diameters, wherein through holes through which the linear spring passes are formed in the groove, and (3) one step, wherein a groove is formed in the step, and a through hole through which the linear spring passes is formed at the bottom of the groove. The through hole through which the linear spring passes is formed on the magnet holder of the lens driving device, the step or groove for storing gel is formed around the through hole, thus the gel is not dripped to other members in the process of dispensing, the gel does not flows out and flows downward along the linear spring, and the characteristics of a product are ensured.