Abstract: Based on the Gerschgorin disc theorem and Brauer oval theorem, the upper bound of the spectral radius of Hadamard product of nonnegative matrices is given by applying the fact that the similar matrices have the same eigenvalues, the result obtained depends only on two entries of nonnegative matrices,so that they are easy to calculate. Numerical example shows that the newestimation formula will improve several existing resultsunder certain condition.

Key words: nonnegative matrix, Hadamard product, spectral radius, upper bound