Abstract: The energy consumption of embedded software has become a key factor in embedded system design, and it is a fundamental work of analysis and optimization of energy consumption to measure the energy consumption of embedded software. This paper proposes a statistical model of embedded software energy consumption, including the energy consumptions of processor, memory and I/O controller, etc. Then, by analyzing the instruction cycle of ARM instruction set, a method for computing the instruction cycle number is designed so as to rapidly calculate the processor energy consumption of embedded software. This model has implemented in a high-precision instruction-level energy simulator HMSim. The experimental results show that the error rate of embedded software energy consumption estimated by this model is less than 10% compared with that measured by an electronic instrument. The achieved results also reflect how the embedded system energy consumption is influenced by different software designs.