In traditional Public Key Infrastructure (PKI) system, Private Key could be stored in central database or store distributed in smart-card and delivered to the users. The Private Key is usually protected by passwords that are easily guessed or stolen and thus lead to the collapse of the whole system. Current trend for PKI system is based on physiological and behavioral characteristics of persons, known as biometrics. This approach can increase the security of Private Key because in theory, the biometric features could not be guessed or forged. However, this approach still reveals a gap that is the vulnerability of storage device of Private Key and biometrics data. Malefactors can attack directly to these storage devices and steal user identification information. In this paper, we propose a solution that uses Biometric Encryption Key (BEK) to encrypt Private Key and protect Private Key in a secure way for both of two these kind of information. We also present the BEK generation algorithm and the BioPKI system to support this solution and then we illustrate the experimental results.