Abstract: The present invention provides a connector assembly, which includes a USB (Universal Serial Bus) plug and a USB receptacle. The plug and receptacle both have a plurality of first contacts and second contacts. The first contacts include a pair of power contacts and a pair of signal contacts, and the second contacts are composed of a pair of new signal contacts. When the plug mates with the receptacle, the first and the second contacts of the plug and receptacle connect electrically with each other correspondingly whereby the connector assembly of the present invention has a more powerful signal transmission function.