Let r, s be two parameters chosen from ℂ* such that rmsn = 1 implies m = n = 0. We compute the derivations of the two-parameter quantized enveloping algebra and calculate its first degree Hochschild cohomology group. We further determine the group of algebra automorphisms for the two-parameter Hopf algebra . As a result, we determine the group of Hopf algebra automorphisms for .