### FromĀ LIGO-Virgo detections to the measurement of the expansion rate of theĀ Universe

The discovery of gravitational-wave from the binary mergers and the joint detection of the electromagnetic counterparts have triggered extensive exploration of gravitational-wave science. In this talk, I will discuss the gravitational-wave detection statistics, the electromagnetic follow-up strategies, and focus on one of the many scientific outcomes enabled by the gravitational-wave/electromagnetic-wave multimessenger astronomy--to measure the expansion rate of the Universe. In particular, I will talk about the precision of Hubble constant measured by this method and the expected challenges.