It is well known in literature that further stages of flow separation and vortex breakdown around wings can be able to cause stall of wings. These formations must be investigated carefully for new plane types. However, some limited studies are available, especially on lambda wing for high angles of attack. In this study, effect of angle of attack on flow characteristics and vortex breakdown around a lambda wing is investigated with a constant Reynolds number of 10000. Computational fluid dynamic analysis is used and results of high angles of attack of the wing are given up to 450 which are not available in literature. Open water channel simulation is used. Vortex breakdown initially begins at an angle of 170 and it almost reaches to tip of wing when angle of attack is equal to 250. Vortices get stronger at further increments of angle of attack and they become to nearly equal length of wing at 450. Rounding effect of leading edges is investigated for decreasing vortex magnitudes. Streamline, particle injection, iso value of vortices and location of stagnation points are given, and they are discussed in detail.