In recent years, from the viewpoint of saving energy, it is requested that the toner can be fused at lower energy. In NIP19, it was reported that the toner containing crystalline polyester exhibited excellent fusing ability. And the melting point of crystalline polyester is effective on fusing ability.On the other hand, the speed of machine system is increasing year by year. So high durability toner is requested as well. However, it was very difficult to satisfy high durability and excellent fusing ability at the same time.In this study, we developed high molecular weight crystalline polyester. Durability of the toner containing crystalline polyester is improved by increasing molecular weight of crystalline polyester. And the melting point of crystalline polyester is not changed even if its molecular weight is higher. So its good fusing ability can be kept. Furthermore, high molecular weight crystalline polyester shows high elasticity above its melting point. Because of that, anti-hot offset property of the toner is also improved.