A lens assembly comprising: a first lens (401, 501, 601, 701, 801, 901) having positive refractive power and including a subject side surface being convex; a second lens (402, 502, 602, 702, 802, 902) having negative refractive power; a third lens (403, 503, 603, 703, 803, 903) having negative refractive power and including a subject side surface and an image sensor side surface being convex toward an image sensor side in a center portion thereof, through which an optical axis passes; a fourth lens (404, 504, 604, 704, 804, 904) having negative refractive power and including a subject side surface and an image sensor side surface being convex toward an image sensor side in a center portion thereof, through which an optical axis passes; and a fifth lens (405, 505, 605, 705, 805, 905) having positive refractive power, wherein the first lens, the second lens, the third lens, the fourth lens, and the fifth lens are sequentially arranged from a subject to an image sensor along the optical axis, wherein the lens assembly satisfies a condition defined by 0.6 < TTL / ImgH < 1, wherein "TTL" represents a distance from the subject side surface of the first lens to an imaging surface of the image sensor, and "ImgH" represents a maximum image height of an image formed on the imaging surface; and wherein the lens assembly satisfies a condition defined by 1.5 < T 57 / T 67 < 2.5, wherein "T57" represents a distance from a subject side surface of the third lens (403, 503, 603, 703, 803, 903) to a subject side surface of the fourth lens (404, 504, 604, 704, 804, 904), and "T67" represents a distance from the image sensor side surface of the third lens to the subject side surface of the fourth lens. a first lens (401, 501, 601, 701, 801, 901) having positive refractive power and including a subject side surface being convex; a second lens (402, 502, 602, 702, 802, 902) having negative refractive power; a third lens (403, 503, 603, 703, 803, 903) having negative refractive power and including a subject side surface and an image sensor side surface being convex toward an image sensor side in a center portion thereof, through which an optical axis passes; a fourth lens (404, 504, 604, 704, 804, 904) having negative refractive power and including a subject side surface and an image sensor side surface being convex toward an image sensor side in a center portion thereof, through which an optical axis passes; and a fifth lens (405, 505, 605, 705, 805, 905) having positive refractive power, wherein the first lens, the second lens, the third lens, the fourth lens, and the fifth lens are sequentially arranged from a subject to an image sensor along the optical axis, wherein the lens assembly satisfies a condition defined by 0.6 < TTL / ImgH < 1, wherein "TTL" represents a distance from the subject side surface of the first lens to an imaging surface of the image sensor, and "ImgH" represents a maximum image height of an image formed on the imaging surface; and wherein the lens assembly satisfies a condition defined by 1.5 < T 57 / T 67 < 2.5, wherein "T57" represents a distance from a subject side surface of the third lens (403, 503, 603, 703, 803, 903) to a subject side surface of the fourth lens (404, 504, 604, 704, 804, 904), and "T67" represents a distance from the image sensor side surface of the third lens to the subject side surface of the fourth lens.