A control device for a hydraulic traveling device, wherein the hydraulic traveling device comprises: a hydraulic transmission (30,40) constituted by having a hydraulic pump (31,41) of variable capacity type, which is driven by an engine, and a hydraulic motor (32,42) driven by discharged oil from the hydraulic pump; a traveling device (5,5) that is rotatably driven by the hydraulic motor; a travel operation device, such as a lever for operating the driving process of the traveling devices that is operated by an operator so as to instruct a traveling speed by the traveling device; a charge pump driven by the engine for supplying a charging oil to the hydraulic transmission through a charging oil passage; and a charging pressure control valve for adjusting a hydraulic pressure inside the charging oil passage into a charging hydraulic pressure (Pch), and wherein the control device comprises, an engine rotation sensor for detecting actual rotation speed (Nea) of the engine; a first control valve for adjusting the charge hydraulic pressure inside the charging oil passage in accordance with the actual rotation speed of the engine detected by the engine rotation sensor so as to generate an engine rotation-related control hydraulic pressure (Pe); variable capacity control actuators (31a,31b,41a,41b) for variably controlling discharging capacity of the hydraulic pump; a second control valve for adjusting the engine rotation-related control hydraulic pressure (Pe) in accordance with the operation of the travel operation device so as to generate a capacity control hydraulic pressure (PcL, PcR) and for supplying the capacity control hydraulic pressure (PcL, PcR) to the variable capacity control actuators; wherein variable capacity controlling of the hydraulic pump is carried out by the variable capacity control actuators, characterized in that; the control device further comprising: an accelerator operation device (53,54) that is operated so as to instruct an engine driving operation; an engine control device for carrying out a driving control operation on the engine in accordance with the operation of the accelerator operation device; and a target engine rotation setting device for setting a target engine rotation speed (Neo) in accordance with the operation of the accelerator operation device; wherein the first control valve adjusts and generates the engine rotation-related control hydraulic pressure (Pe) so as to make a difference between the actual engine rotation speed (Nea) detected by the engine rotation sensor and the target engine rotation speed (Neo) set by the target engine rotation setting device smaller. a hydraulic transmission (30,40) constituted by having a hydraulic pump (31,41) of variable capacity type, which is driven by an engine, and a hydraulic motor (32,42) driven by discharged oil from the hydraulic pump; a traveling device (5,5) that is rotatably driven by the hydraulic motor; a travel operation device, such as a lever for operating the driving process of the traveling devices that is operated by an operator so as to instruct a traveling speed by the traveling device; a charge pump driven by the engine for supplying a charging oil to the hydraulic transmission through a charging oil passage; and a charging pressure control valve for adjusting a hydraulic pressure inside the charging oil passage into a charging hydraulic pressure (Pch), and wherein the control device comprises, an engine rotation sensor for detecting actual rotation speed (Nea) of the engine; a first control valve for adjusting the charge hydraulic pressure inside the charging oil passage in accordance with the actual rotation speed of the engine detected by the engine rotation sensor so as to generate an engine rotation-related control hydraulic pressure (Pe); variable capacity control actuators (31a,31b,41a,41b) for variably controlling discharging capacity of the hydraulic pump; a second control valve for adjusting the engine rotation-related control hydraulic pressure (Pe) in accordance with the operation of the travel operation device so as to generate a capacity control hydraulic pressure (PcL, PcR) and for supplying the capacity control hydraulic pressure (PcL, PcR) to the variable capacity control actuators; wherein variable capacity controlling of the hydraulic pump is carried out by the variable capacity control actuators, characterized in that; the control device further comprising: an accelerator operation device (53,54) that is operated so as to instruct an engine driving operation; an engine control device for carrying out a driving control operation on the engine in accordance with the operation of the accelerator operation device; and a target engine rotation setting device for setting a target engine rotation speed (Neo) in accordance with the operation of the accelerator operation device; an accelerator operation device (53,54) that is operated so as to instruct an engine driving operation; an engine control device for carrying out a driving control operation on the engine in accordance with the operation of the accelerator operation device; and a target engine rotation setting device for setting a target engine rotation speed (Neo) in accordance with the operation of the accelerator operation device; wherein the first control valve adjusts and generates the engine rotation-related control hydraulic pressure (Pe) so as to make a difference between the actual engine rotation speed (Nea) detected by the engine rotation sensor and the target engine rotation speed (Neo) set by the target engine rotation setting device smaller.