The results of studies of determining the rational parameters of excavator-automobile complexes in the development of mineral deposits in the conditions of powerful deep quarries for the extraction of iron ore are presented. It has been established that the optimum ratio of the capacity of the dump truck body to the capacity of the excavator bucket is the most important condition for the high-performance use of excavators and vehicles with a minimum cost of mining transportation. An analytical dependence was obtained for determination the necessary ratio between the capacity of the dump truck body and the capacity of the excavator bucket to achieve the maximum possible productivity of the excavator-automobile complex when loading and transporting any type of rock, taking into account the characteristics of the rock mass, the duration of loading it by excavator, the duration of exchange operations, horizontal and inclined sections of the route, the elevation of the rock mass by road and average slope of the inclined sections of the route. For the quarry conditions of the Poltava Mining and Processing Plant, the existing equipment of the excavator-automobile complex has been analyzed, the necessary capacity of excavator buckets for the selected routes has been calculated, and the most rational associations of mining and transport equipment have been recommended. It was found that for overburden operations, the most effective of the existing fleet of excavators will be Komatcu PC-3000 with a bucket capacity of 15 m3 (the calculated value of the optimal capacity of the excavator bucket is 15.3 m3) provided that the rock mass is transported by Hitachi EH-3500A dump truck with a body capacity of 115.1 m3. It is advisable to carry out mining operations with excavators with a bucket capacity of 13.5 m3 and 11.5 m3 using the Hitachi EH-3500A dump truck. The results of scientific research allow us to determine the rational parameters of excavator-automobile complexes for the existing mining-geological and technological conditions of any quarry to optimize the structure of complex mechanization of mining operations.