A dual-interface computer interface card includes a circuit board. The circuit board includes an ExpressCard connector, a USB connector, a control circuit, a converter, two USB signal traces, two DC traces. The two USB traces are electrically connected with the ExpressCard connector and the USB connector respectively. The two DC traces are electrically connected with the converter and respectively with the ExpressCard and USB connectors. The control circuit, subject to the required DC operation voltage, is optionally connected with one of the two DC traces, while another DC trace is connected with the converter to convert its DC voltage level into the DC voltage level required by the control circuit. Accordingly, the computer interface card can be connected with the computer system optionally by one of the connectors thereof for transmission of USB signals therebetween.