  By the end of 2014, a cosmic ray muon telescope was installed at Zhongshan
Station in Antarctic and has been continuously collecting data since then. It
is the first surface muon telescope to be built in Antarctic. In June 2015,
five CMEs were ejected towards the Earth initiating a big large Forbush
decrease (FD) event. We conduct a comprehensive study of the galactic cosmic
ray intensity fluctuations during the FD using the data from cosmic ray
detectors of multiple stations (Zhongshan, McMurdo, South Polar and Nagoya) and
he solar wind measurements from ACE and WIND. A pre-increase before the shock
arrival was observed. Distinct differences exist in the timelines of the
galactic cosmic ray recorded by the neutron monitors and the muon telescopes.
FD onset for Zhongshan muon telescope is delayed (2.5h) with respect to SSC
onset. This FD had a profile of four-step decrease. The traditional one- or
two-step classification of FDs was inadequate to explain this FD.
