This paper presents a four legs robotic dog with an interactive-learning system. There are four sub-systems; including physiology, feeling, learning, and behavior are built on the robot for the interactive-learning system. Three different feelings are designed in the robot. The batteries and the motors statuses are transferred to feeling of hunger and fatigue of the pet robot. Curiosity, which let the pet robot want to play with human, is also one feeling for the pet robot. The pet robot doesn't know how to react when it feels something. A Neural-Network system is implemented to build the relationship between the behaviours and the feeling. As frequency of interaction increasing, the pet robot is able to choose the right behaviours more often. Experimental results show the efficiency of the proposed method.