Disclosed is a collar apparatus for animal training with a length adjustable leash. The collar apparatus applies a vibration or an electrical stimulation to an animal while automatically adjusting a length of a leash connected to an animals body. Accordingly, it is possible to train the animal to desirably act by applying the electrical stimulation or the vibration to the animal through adjusting the length of the leash connected to the animals body when the animal acts with undesirable behavior.
