A deposition mask assembly having a plurality of deposition masks consecutively arranged in parallel is discussed. The deposition mask has a frame coupled with the plurality of deposition masks, wherein cross section of one end of each deposition mask having first and second sectors which are asymmetric and meet each other at a first contact point, wherein the first sector has a first radius and a first center angle, and connected to an upper surface of the deposition mask, the second sector has a second radius different from the first radius and a second center angle different from the first center angle, and connected to a lower surface of the deposition mask, and the contact point is asymmetric, pointed and protruded horn-shaped or arrow-shaped.