A wireless telemetry measurement system, using ISFETs, was developed for environmental monitoring applications, industrial processes, medical treatments and so on. This system is composed of the measurement part located at remote site and a personal computer(PC) which control whole instrument process. The measurement part transmits measured data to the PC by RF transceiver, and transmitted data are analyzed and handled in the PC. Proposed system utilizing time division multiplexing for the transmission of 3channel ISFET signal. The measurement part has an identification number(ID) so that the PC controls many measurement parts separately. Experiments were performed using pH-ISFETs, and the implemented system operates well within designed specification and accuracy of 0.1 pH.