Transfusion monitoring and controlling system of wireless communication is designed for avoidance of medical accident due to inconsiderate care. This system is based on RS-485 bus protocol to build the communication network, consisting of master computer and slave computer. STM32F103R8T6 MCU is the core of the master computer, and MSP430F2132 MCU for slave computer. The wireless transmission of data between master computer and slave computer can be done by nRF905 wireless transceiver module. One new calculation of drop speed is used for better real-time displaying thereof. Provided that abnormal occurrence is during the transfusion, the transfusion tube will be closed by controlling order from system, in order to protect the patient.