Telemetric monitoring and control are the two critical aspects for a robot-rat.Development in this work is a telemetric system to record the electro-encephalogram(EEG) from adult freely roaming animals.The system consists of two separated components:the transmit-end system,which consists of the preamplifier,the LPF(low-pass filter) and the transmitter,and the receive-end system,which consists of the receiver,the interface of receive-end and PC.The transmit-end system with light weight(10 g including battery) and small size(20 mm×50 mm) is fettered on the back of the rat.The EEG signal is modulated at the RF frequency of 2.4 GHz by nRF24E1 and transmitted by the antenna.The system can measure the EEG signal of the rat in freely roaming over a wireless transmission distance up to 8 m,and provide a new platform for behavioral and neurophysiological experiments. Telemetric monitoring and control are the two critical aspects for a robot-rat. Development in this work is a telemetric system to record the electro-encephalogram (EEG) from adult freely roaming animals.The system consists of two separated components: the transmit-end system consisting of the preamplifier, the LPF (low-pass filter) and the transmitter, and the receive-end system, which consists of the receiver, the interface of receive-end and PC. (10 g including battery) and small size (20 mm × 50 mm) is fettered on the back of the rat. The EEG signal is modulated at the RF frequency of 2.4 GHz by nRF24E1 and transmitted by the antenna. The system can measure the EEG signal of the rat in freely roaming over a wireless transmission distance up to 8 m, and provide a new platform for behavioral and neurophysiological experiments.