Abstract: Disclosed are an online identity authentication system using a real card, and a method thereof. The present invention enables identity authentication to be conducted by using a user's real bank card at the time of a mobile financial transaction using a smart phone such that a financial transaction can be conducted as if the financial transaction is conducted at an ATM of an offline bank, without an authentication certificate being saved separately. Accordingly, the present invention enables online financial transactions to be more conveniently conducted and security to be maintained. In addition, when identity is authenticated, a real bank card is read at a card reader unit and credit card information is transmitted, and thus the present invention has an advantage of enabling secure payments to be conducted without the risk of hacking.