provided are a variable power optical system in which the value of the entire length with respect to the image height is reduced and the aberration is well corrected , and an image pickup device comprising the same . specifically provided is a variable power optical system comprising , in order from the object side , at least a first lens group having negative refractive power , a variable power group having positive refractive power , and a final lens group having positive refractive power , wherein the variable power group is provided with , in order from the object side , a first lens element having positive refractive power , a second lens element , and a third lens element , the second lens element has a convex shape on the object side , and the final lens group comprises a positive lens , the variable power optical system satisfying the following conditional expression : 10 ≦ vdlg ≦ 45 − 1 . 0 & lt ;/& lt ; 1 . 0 where vdlg is the abbe number of the positive lens of the final lens group with respect to the d line , r2a is the curvature radius of the object - side surface of the second lens element , and r2b is the curvature radius of the image - side surface of the third lens element .