“…Up to now, the spectral radius λ 1 (G) and the Laplacian spectral radius µ 1 (G) of G have been extensively investigated for a long time (see, for example, [1], [2], [4], [5], [6], [7], [8], [11], [12], [13] and the references therein). Recently, Liu and Lu [8] introduced two new notations ( α t) i and ( α m) i and obtained some new bounds for the Laplacian spectral radius µ 1 (G) of G. Motivated by this technique, we present some new bounds of λ 1 (G) and µ 1 (G) with parameter α and characterize some extreme graphs which attain these upper bounds.…”