The invention provides an imaging
system, which comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens from the light incident side to the light emergent side of the imaging
system, a second lens; the third lens has positive focal power; the fourth lens has focal power; the surface, facing the light incident side, of the fifth lens is a
concave surface, and the surface, facing the light emergent side, of the fifth lens is a convex surface; the sixth lens has negative focal power; the surface, facing the light incident side, of the seventh lens is a
concave surface, and the surface, facing the light emergent side, of the seventh lens is a convex surface; the eighth lens has focal power; the surface, facing the light emitting side, of the ninth lens is a convex surface; wherein the half ImgH of the
diagonal length of an effective pixel area on the imaging surface of the imaging
system and the on-
axis distance TTL from the surface, facing the incident side, of the first lens to the imaging surface meet the condition that TTL / ImgH is smaller than 1.3. The problem that in the prior art, an imaging system is poor in performance is solved.