  Uncertainty principle is the basis of quantum mechanics. It reflects the
basic law of the movement of microscopic particles. Wigner-Yanase skew
information, as a measure of quantum uncertainties, is used to characterize the
intrinsic features of the state and the observable. In this paper, we mainly
investigate the sum uncertainty relations for both quantum mechanical
observables and quantum channels based on skew information. We establish a new
uncertainty relation in terms of Wigner-Yanase skew information for $n$
observables, which is saturated (thus it holds as equality) for two
incompatible observables. We also present two uncertainty relations for
arbitrary finite $N$ quantum channels by using skew information. Our
uncertainty relations have tighter lower bounds than the existing ones.
Detailed examples are provided.
