In this paper,we compared the following four models:Jump-Arch diffusion model,jump diffusion model,arch diffusion model and diffusion model from four aspects.We found that the Jump-Arch model is the best of the four models.It can explain and forecast best the behavior of the volatility of the interest rates.Jump is not only the source of the mean-reversion of the interest rates,but also the main source of the volatility of the interest rates.So when we model the behavior of interest rates,the ju...