In this paper, we propose a measuring system of physiological signals including body temperature and blood pressure based on the concepts of ubiquitous healthcare. The physiological signals are transferred to a server via personal digital assistant (PDA) by Bluetooth technology. In order to protect the patients’ privacy and preserve the security of the relevant to measured signals, we use AES and RSA algorithms to encrypt the physiological data of the cared people and the key of AES algorithm respectively. The approach provides a well-compromise between the speed of encryption/decryption and the information security. In contrast to the conventional nursing, that is, via hand write and key-in the data to a computer, our proposed approach can effectively improve the efficiency, correctness, and security.