Abstract: An infant condition monitoring system has a sensor sheet including uniformly arranged plural pressure sensitive load cells. An ECU in an electronic unit connected to the sensor sheet calculates an infant's breathing signal, sleeping posture and weight data. Those signal and data are converted into data signals to modulate a carrier signal thereby. A transmitter in the electronic unit transmits a radio signal resulting from the modulation. A monitoring unit is constructed to be carried by a care provider. A receiver in the monitoring unit demodulates the received radio signal. An ECU reproduces the data signals including the breathing signal, sleeping posture and weight data, and determines a respiration rate, sleeping posture and weight. A display displays the respiration rate, sleeping posture and weight, and a speaker produces an output sound in correspondence with the breathing signal.