To provide a high-quality mobile service in a safe way, many techniques for location anonymity have been proposed in recent years. Advanced location-based services such as mobile advertisement services may use not only users' locations but also users' attributes. However, the existing location anonymization methods do not consider attribute information and may result in low-quality privacy protection. In this paper, the authors propose the notion of visibility, which describes the degree that an adversary can infer the identity of the user by an observation. Then, they present an anonymization method which considers not only location information but also users' attributes. They show several strategies for the anonymization process and evaluate them based on the experiments.