Multiple processor cores are built within a chip by advanced VLSI technology. With the decreasing prices, multi-core processors are widely deployed in both server and desktop systems. The workload of multi-threaded applications could be separated to different cores by multiple threads, such that application threads can run concurrently to maximize overall execution speed of the applications. Moreover, for the green trend of computing nowadays, most of modern multi-core processors have a functionality of dynamic frequency turning. The power-level tuning techniques are based on Dynamic Voltage and Frequency Scaling (DVFS). In order to evaluate the performance of various power-saving approaches, an appropriate technique to measure the power consumption of multi-core processors is important. However, most of approaches estimate CPU power consumption only from CMOS power consumption data and CPU frequency. These approaches only estimate the dynamic power consumption of multi-core processors, the static power consumption is not be included. In this study, a hardware approach for the power consumption measurement of multi-core processors is proposed. Thus the power consumption of a CPU could be measured precisely, and the performance of CPU power-saving approaches can be evaluated well.