In this study, to estimate the suspended load of sediments entering the reservoir of Dez dam located in southwestern Iran, various hydrological methods were used including annual, seasonal, and monthly high water-low water, in two methods (USBR, FAO) and the ratio method.The results showed that the ratio method had the lowest percentage of relative error among the hydrological methods tested, so it was introduced as the optimal method.Various hydraulic methods such as Ratner, Van Rijn, Meyer-Peter and Müller, Müller and Schoklitsch were used to estimate the load of the bed entering the reservoir of Dez Dam. This method was used for the days when the bed load was measured and sampled at the hydrometric station located at the entrance to the reservoir of Dez Dam (Tele Zang station), and based on this, the ratio of bed load to suspended load was obtained.The results indicated that with increasing flood flow rate, the share of bed load relative to suspended load is decreased so that the value of suspended bed load coefficient from 42% for a minimum flow rate of 158 m3/s to 1% for a recorded maximum instantaneous flood rate of 6753 m3changed per second. This result also shows that with increasing flow rate, the ratio of bed load to suspended load is reduced. These results show that the values obtained for the average ratio of bed load to suspended load for all methods except the FAO annual method are not significantly different at the confidence level of 90% and on average, this value is equal to 12%.