Abstract: The problem of asymmetric jet formation during the two-flow collision is theoretically unsolved yet, owing to steady solutions indeterminacy. Starting with special jets, we analyze the asymmetry between initial configuration of two incoming streams and their interaction. Based on principle of minimum kinetic energy, the close condition of equations is built, which is satisfied with the problem of asymmetric collision. The geometrical theory of asymmetric jet formation is given. Taking the collision of planar incoming streams with unequal thickness for example, we predict outgoing streams direction and size as a function of initial configuration of the incoming streams, which are in agreement with numerical results.