Abstract: Based on the characteristic of the branch instruction,the impact of branch behavior and branch prediction technique on the CPI stacks components of the embedded single-issue processor is analyzed in this paper,furthermore the accurate timing model of the branch predictor is designed in RTL-level,and the characteristic of branch instruction and the performance of branch predictor are also studied through hardware simulation.In our experiment the correspondent statistical properties of the branch instruction when the behavior of miss or hit in the branch predictor happens are recorded,proving the legitimate conclusion of the correlativity between the branch predictor and the CPI stacks components and providing the design and optimization of the branch predictor for the embedded single-issue processor with accurate experimental basis.