  Besides quantum entanglement and steering, quantum coherence has also been
identified as a useful quantum resource in quantum information. It is important
to investigate the evolution of quantum coherence in practical quantum
channels. In this paper, we experimentally quantify the quantum coherence of a
squeezed state and a Gaussian Einstein-Podolsky-Rosen (EPR) entangled state
transmitted in Gaussian thermal noise channel, respectively. By reconstructing
the covariance matrix of the transmitted states, quantum coherence of these
Gaussian states is quantified by calculating the relative entropy. We show that
quantum coherence of the squeezed state and the Gaussian EPR entangled state is
robust against loss and noise in a quantum channel, which is different from the
properties of squeezing and Gaussian entanglement. Our experimental results
pave the way for application of Gaussian quantum coherence in lossy and noisy
environments.
