Abstract: A high-speed network apparatus and a self-testing method thereof are provided. The method is to configure a first network interface to transmit a plurality of test Ethernet frames to a second network interface via a network cable continuously during a default time interval, count a number of the transmitted test Ethernet frames, compare the counted number with a default value, and issue a notification according to a result of comparison. The present disclosed example can test a transmission speed of a high-speed network apparatus effectively without any additional test apparatus, and can reduce a cost of test significantly.