An electrically tunable zooming LCOS pico projector using composite liquid crystal (LC) lenses is demonstrated. The composite LC lens consists of two built-in sub-lenses: one is an electrically tunable focusing lens controlled by a LC layer and the other is a fixed focused polymeric lens. The zoom ratio of the electrically tunable zooming pico projector can reach 2.5 : 1 when the screen distance at 20 cm. The tunable focusing ranges are 200 cm to ∼ 10 cm and the response times is around 3.8 sec. The image performance of the electrically tunable focusing LCOS pico projector is also demonstrated.