In Ethiopia, the operation of tomato vegetable cultivation has been dominated by manual transplanting over the open-field cultivation practices, which is labor-intensive, time consuming, expensive operation, and requires about 40% of the total operational time with 284 man-hours/ha needed for cultivation. In order to overcome the high demand rate of vegetable crops, it is very important to consider an automatic tomato transplanter to apply transplanting operation at high speed resulting in high production rate with low labor cost. The pick-up device is the key to consider automatic transplanting operation, thus a pneumatic driven reciprocating-type automatic whole-row seedling pick-up device for development of automatic tomato transplanter was designed with its matching control system. The pick-up device, consisting of a path manipulator and eight grippers, reciprocates in predetermined trajectory of picking gripper. After establishing the closed-loop vector equations for the rod-group of the picking mechanism, the required picking-trajectory was planned using MATLAB polynomial fitting. Then, the trajectory of the path manipulator was determined and the shape of the copying groove was fitted by using MATLAB combined envelope method. To verify the consistency of the simulated trajectory and theoretical trajectory, the 3D model of pick-up device was developed by SOLIDWORKs and the kinematics simulation was verified using ADAMS MSc software with the uprightness of 89.75° at dropping position that is close to 90°. The driving air cylinder and photoelectric sensor were used to control the reciprocating movement of the grippers for picking and dropping seedlings at designated positions in the predetermined paths. The synchronized control scheme of seedling feeding, picking and dropping was designed, then a PLC control program was compiled that included accurate seedling feeding, seedling picking in perpendicular direction to the plug tray, and returning to fixed vertical position rapidly for seedling dropping. When the maximum picking frequency is 24 plants/min/gripper, simulation results shows that the optimal seedling pushing time should be 0.0833 seconds at 40 mm cylinder stroke and 0.48 m/s seedling pushing speed. Keywords. Pick-up device, whole row, reciprocating movement, predetermined trajectory, gripper, copying groove, control system, transplanter