Abstract: Wireless Sensor Networks (WSNs), which has been widely used in the practical systems, is one of the new research areas in information technology. The transmission scheme，which is used in WSNs， determines the transmission reliability and battery power efficiency of the WSNs. That is, transmission scheme is one of the key factors for the system performance of WSNs. In order to analysis and compare Frequency- Shift-Keying(FSK) and On-Off-Frequency-Shift-Keying(OOFSK), which have been widely used in WSNs, more efficiently in WSNs，we presents a method of comparing the comprehensive performances of WSNs nodes with FSK or OOFSK, when WSNs nodes are powered by battery. We analysis the performances of FSK and OOFSK with the view point of bit error rate and battery efficiency. From the numerical results, we find that OOFSK can achieve better comprehensive performance than FSK for some signal to noise ratio conditions, and the comprehensive performance gain of OOFSK becomes higher significantly when the duty factor v of OOFSK modulation gets lower. In addition, as for comprehensive performance gain of OOFSK, the duty factor v of OOFSK modulation has more significant impact than that of the signal to noise raito.