The working dog summary will introduce different types of working dogs currently used over the world and relevant knowledge. This includes herding dogs, sled dogs, search and rescue dogs, detector dogs, guide dogs for the blind, hearing dogs for the deaf, service dogs for the disabled, therapy dogs and companion dogs for the sick/elderly etc. Although each work has its own unique characteristic and function, they were all based on canine’s inherent abilities and willingness to provide service to men. This was utilized and developed into different fields to enhance the life quality of human society.