As wireless network technology and various mobile communication equipments have widely used and rapidly developed, many research workers are studying about a measurable system for several medical data or bio-signals, such as electrocardiogram, pulse-oximetry and so forth, by wireless. And, even generic people who are in a good state of health as well as patients in the hospital, whose concern and care about healthcare has increased greatly, so many research workers are studying about Ubiquitous Healthcare of new technology. This technology will offer natural medical services freely in anywhere and in a quiet way, even if people can not go to hospital. Our research made a possibility to measure environment data in each infant incubator by using temperature and humidity sensor, prior to measure directly bio-signals of patients. Each sensor was composed of wireless network based on TinyOS, and that wireless network connected to Personal Digital Assistants(PDA). So we were studied about telemetry system by using wireless sensor network. It was researches about telemetry system to measure environment data in infant incubator before, by web-based RF modules. But they has problems that incubator's movement restriction by wire, wire net's limitation. We solved these problems by organizing wireless sensor network that connected together sensors and measurement devices. This wireless sensor network organization, based on TinyOS, is possible to receive sensor's data of long distance by a relay station and to save power. In future, this network will be basic of Ubiquitous Healthcare as well as medical information system in hospital.