A complementary metal-oxide-semiconductor depth sensor element having a photogate formed in a photosensitive area on a substrate. A first transfer gate and a second transfer gate are formed respectively on two sides of the photogate in intervals. A first floating doped area and a second floating doped area are formed respectively on the outer sides of the first transfer gate and the second transfer gate. A semiconductor area is formed on the substrate. A lightly doped region is formed on the semiconductor area. The photogate, the first and second transfer gates and the first and second floating doped area are commonly formed on the lightly doped region. With the lightly doped region, the linear performance that the majority carriers move in the photogate is also affected to achieve the purpose for increasing the reaction rate.