An operating method of a taping machine comprising a conveying mechanism which defines a sliding plane, for conveying a plurality of boxes to be sealed with adhesive tape, and comprising at least a conveying unit for the displacement of said boxes, set in motion by an actuator controlled by a drive, at least a tape applicator (4, 5) provided above said sliding plane, meant to apply sealing adhesive tape on said plurality of boxes during the displacement thereof, a passage sensor, arranged fixed with respect to said sliding plane, apt to detect the moving position of at least a vertical surface of said boxes and output a respective sensor signal, the method comprising the step of conveying a plurality of boxes to be sealed with adhesive tape on said sliding plane by said conveying mechanism toward said tape applicator (4, 5) meant to apply sealing adhesive tape on said plurality of boxes during the displacement thereof, said tape applicator (4, 5) including at least an inlet applicator roller and an outlet applicator roller being meant to contact a surface of said boxes during application of tape, wherein, when a front vertical surface of the box is detected by said passage sensor, a position of the front vertical surface of the box along the path is computed by determining a reduction ramp in the speed profile of said actuator characterized in that a conveying feed speed profile of said boxes is varied after said front vertical surface of the box has come into contact with said inlet applicator roller and a point of application of the adhesive tape has exceeded a transition edge with a horizontal side, returning to a level of a maximum speed (Vmax) by means of an appropriately shaped ascending ramp and varied again when the current position of a rear vertical surface of said boxes has almost reached the position of said outlet applicator roller, having a reduction ramp, to a minimum speed value (Vmin) up to an end point of application of said adhesive tape, and finally, when said boxes move away from said tape applicator (4, 5), said speed profile has a new ascending ramp towards a maximum speed (Vmax). at least a conveying unit for the displacement of said boxes, set in motion by an actuator controlled by a drive, at least a tape applicator (4, 5) provided above said sliding plane, meant to apply sealing adhesive tape on said plurality of boxes during the displacement thereof, a passage sensor, arranged fixed with respect to said sliding plane, apt to detect the moving position of at least a vertical surface of said boxes and output a respective sensor signal, the method comprising the step of conveying a plurality of boxes to be sealed with adhesive tape on said sliding plane by said conveying mechanism toward said tape applicator (4, 5) meant to apply sealing adhesive tape on said plurality of boxes during the displacement thereof, said tape applicator (4, 5) including at least an inlet applicator roller and an outlet applicator roller being meant to contact a surface of said boxes during application of tape, wherein, when a front vertical surface of the box is detected by said passage sensor, a position of the front vertical surface of the box along the path is computed by determining a reduction ramp in the speed profile of said actuator characterized in that a conveying feed speed profile of said boxes is varied after said front vertical surface of the box has come into contact with said inlet applicator roller and a point of application of the adhesive tape has exceeded a transition edge with a horizontal side, returning to a level of a maximum speed (Vmax) by means of an appropriately shaped ascending ramp and varied again when the current position of a rear vertical surface of said boxes has almost reached the position of said outlet applicator roller, having a reduction ramp, to a minimum speed value (Vmin) up to an end point of application of said adhesive tape, and finally, when said boxes move away from said tape applicator (4, 5), said speed profile has a new ascending ramp towards a maximum speed (Vmax). after said front vertical surface of the box has come into contact with said inlet applicator roller and a point of application of the adhesive tape has exceeded a transition edge with a horizontal side, returning to a level of a maximum speed (Vmax) by means of an appropriately shaped ascending ramp and varied again when the current position of a rear vertical surface of said boxes has almost reached the position of said outlet applicator roller, having a reduction ramp, to a minimum speed value (Vmin) up to an end point of application of said adhesive tape, and finally, when said boxes move away from said tape applicator (4, 5), said speed profile has a new ascending ramp towards a maximum speed (Vmax).