Provided are a system for transmitting interworking data in heterogeneous networks and a method thereof. The system for transmitting interworking data in heterogeneous networks and a method thereof capable of greatly improving convenience and reducing counseling time, by downloading and installing data transmission applications to a customer terminal and an ARS counselor terminal, respectively, allowing the ARS counselor to simply select specific data from complex and hard information upon ARS counseling in a state in which he/she sorts and stores in advance information to be transmitted as data upon the ARS counseling and transmit the selected specific data to the customer terminal, and allowing the remote counselor to control a page for the data transmitted to the customer terminal to be output.