Human violence against animals has existed since the beginning of history. Such violence has almost always been regarded as acceptable for human interests and as an exercise of the owners' justifiable dominion over their property. From the middle of the 19th century, however, laws forbidding intentional animal cruelty were gradually enacted in England and the United States. In 1641, the Massachusetts Bay Colony adopted a legal code, "The Body of Liberties", which prohibited cruelty to animals. From early 19th century to early 20th century, all 50 states have enacted anticruelty statutes to protect animals against unnecessary suffering or cruel mistreatment. These statutes, however, vary considerably in the animals that are covered, the animal abuser's required state of mind, the specific acts that are prohibited, and the penalties. Some problems have been pointed out in these statutes. For example, broad exemptions, insufficient penalties, lax enforcement etc. In addition to individual states, there are three main federal statutes relating to animal welfare: "Twenty-Eight Hour Law(1873)", "Humane Slaughter Act(1958)" and "Animal Welfare Act(1966)". However, there is no federal anticruelty statute in the United States. The Korea Animal Protection Law was first adopted in 1991. However, the law contained lots of problems. Animal protection organizations in Korea have actively participated in the revision of the law. After many years of campaigning, petitioning and public hearings, Korea's Animal Protection Law was revised on January 26th, 2007 and is effective from January 27th, 2008. Major improvements in the new legislation are: (i) introduction of the animal registration system, (ii) strengthened protection and management for stray animals, (iii) reinforcement of companion animal owners' supervision duties, (iv) specifications of animal cruelty, (v) provision of protection regulations for animal transportation, (vi) establishment of animal experimentation ethics committee, (vii) prohibition of acts of causing harm to animals for the purpose of gambling, advertisement and entertainment, (viii) introduction of animal protection warden and honorary warden system, (ix) reinforcement of punishment for violations (maximum fines for animal cruelty increase from 200,000 Won to 5,000,000 Won). The revision is a vast improvement over the original, working not only to amend and strengthen existing legislation, but also adding new legislation to address many systems for enhancing of animal welfare. Plenty of problems, however, required by the animal protection groups have not been reflected in the new animal protection law revised animal protection law. They are, for example: (i) expansion of scope of animals protected by the law, (ii) expansion of definition and types of animal abuse, (iii) expansion of prohibition on animal testing, (iv) variety of punishment, (v) prohibition of slaughtering dogs for edible purpose, (vi) forfeiture of abused animal etc. They must be re-discussed in the next revision. Enhancing the status of animals in the legal system is a critical task. We have taken a big step on the road to animal welfare in Korea. However, we still have a long way to go.