The personal bio-information supplied from the PHD(Personal Health Device) for personal health management is very sensitive in relation to a personal living body in an aspect of privacy protection. On the assumption thai the information is about a patient, it is more serious problem if it is revealed to a third party. However. the established ISO (International Organizations for Standardization) standard protocol[1] in October 2009 has just considered a transmission part for mutual exchange of bio-information between individuals, but has never actually considered security elements. Accordingly, this paper is to show all sorts of security threats according to personal health management in the u-health environment and security requirements newly.