A novel method based on fourth-order cumulants (FOC) is proposed for direction of arrival (DOA) estimation with uniform linear array (ULA). The method can be applied in the situation that the non-Gaussian independent and coherent signals coexist with unknown coloured Gaussian noise. The method comprises two steps: the first step is to estimate the independent signals, and then they are eliminated; the second step is to resolve the coherent signals with the reconstructed FOC matrix of coherent signals. The proposed method can also be extended to the scenario when independent, partially correlated and coherent signals coexist, and the number of signals resolved by our method can exceed the number of array elements. Simulation results demonstrate the effectiveness and efficiency of our method.