Direction of arrival (DOA) estimation has been discussed extensively in the array signal processing field. In this paper, we focus on the DOA information which is defined as the mutual information between the DOA and the received signal with complex additive white Gaussian noise. A theoretical expression of DOA information with multiple sources is presented in the uniform linear array. Specially, the upper bound of DOA information for sparse sources with high SNR is derived and compared with the information of single source. Moreover, the relationship between Cramer-Rao bound and the upper bound of DOA information is given. Finally, the paper investigate the performance evaluation of estimation based on the DOA information. We define the entropy error (EE) as a new performance evaluation index and find that EE is better than mean square error. Moreover, the lower bound of the EE can be regarded as the Generalized Cramer-Rao bound considering the sources' order in multi-source scenario.