According to the inquiry method, if the pet food trademark has been registered and obtained the exclusive right to use the trademark, then its ownership can be transferred according to law. According to the Trademark Law of People's Republic of China (PRC), a trademark registrant can transfer all or part of his exclusive right to use a trademark to others by signing a trademark transfer agreement. If the trademark is not registered, or the registration is revoked or invalid, then the buying and selling behavior may be risky. If the trademark is legal and valid, the ownership is clear and definite, and a legal trademark transfer agreement is signed and registered, then the trading behavior of the pet food trademark is legal.