A meteorological rocket sonde based on GPS system is developed, which is composed of a microminiature bead form thermistor temperature sensor with rapid response and negative temperature coefficient, a piezoresistive silicon pressure transducer and a GPS-Receiver. Compared with meteorological rocket sondes flight before, this new sonde can make higher accuracy measurement of meteorological parameters on temperature, pressure, density and wind field, and its telemetry receiving equipment is more portable. Besides, simple prelaunch preparation work and high system reliability are two other advantages of it. The launching test of the sonde has been successfully conducted in the Meridian Project, and satisfactory detection results have been obtained.