Abstract: When the interferences are correlated,the signal-eigenvector may shift to the noise space.At this situation,adopting the eigen-space decomposition adaptive algorithms,will not suppress the correlated interferences except the direction vectors of the interferences are same.When the uncorrelated interferences come from same direction,the eigen-space decomposition adaptive algorithms just detect one interference,but the algorithms will suppress the interferences.The simulation result of the MUSIC and Min-norm algorithms are same as the theory.