Abstract: At present, the system of using PKI(public key infrastructure)/CA(certificate authority) technology in the online transaction between Internet Banking and Funding Company is quite few. In order to adapt the increasing business requirement of bank and fund company, after a long-time research on PKI/CA technology and Internet Banking System, this paper presents a solution to implement on-line transaction between Internet Banking and Fund Companies by using the PKI/CA technology. This solution has realized a scure data transmission by digital signature and encryption, guaranteed the information security of customers'. And it has made the transaction more convenient and faster, satisfactorily met the demands of the system by modeling the workflow.