When a neutron star is compressed to huge densities, it may be converted to a strange star. In property of the event/year rate of a neutron star -strange star binary system, we show that the operational phase of advanced gravitational wave detectors may bring up some evidences that such strange stars do exist. Moreover we argue that such a system could be a plausible progenitor to GRB 051103 and GRB 070201, whose non-detection by LIGO last run awaits convincing explanation.