This study presents the result of a case study on the switching over-voltage transients of AC electrified railroad trains equipped with switch-type rectifiers in Taiwan Railway Administration. It was found that new generation of switch-type converters could result in significant over-voltage of magnitude comparable to lightning surge if no proper snubber circuit is used. The switching surge could damage power equipment of nearby trains in the same service zone, as observed in the TRA system. It is recommended that maximum tolerance of switching overvoltage is clearly specified in the procurement phase of new trains with switch-type converters then is accurately verified in the commissioning phase to ensure proper preventive measure has been taken.