A piston pump assembly of an electronic controlled brake device for a vehicle includes: an inlet housing configured to accommodate a reciprocating piston and elastically support the piston; an outlet housing configured to accommodate the inlet housing and form a working chamber that allows a working fluid to be introduced from the inlet housing; an outlet ball valve accommodated in the working chamber to open and close a flow passage of the working fluid that is introduced from the inlet housing to the outlet housing; an outlet spring accommodated in the working chamber to elastically support the outlet ball valve toward the inlet housing; and a damper accommodated in the working chamber and mounted within the outlet spring to allow shape deformation while contacting the outlet ball valve. When the outlet ball valve is pushed and pressed toward an end of the working chamber, the damper generates viscous damping while discharging the accommodated working fluid into the working chamber. Accordingly, it is possible to actively reduce noise or vibration upon initial operation of the electronic controlled brake device or in a low frequency section, thereby improving ride comfort.