Abstract: Recent progress of investigations on sensor placement methods and their evaluation criteria in structural health monitoring are critically reviewed in the paper. Existing influential sensor placement methods are analyzed with emphasize on exposing their mathematical connections and differences, in particular, the relationship between the Effective Independence method and the Modal Kinetic Energy method, the connections between the Effective Independence method and the QR decomposition method and MinMAC method, are discussed in details. Furthermore, a ladder structure is employed as a model to compare the discussed sensor placement methods and traditional five evaluation criteria for sensor placement methods. Finally, an evaluation criterion proposed by the author is discussed through its connection with two traditional evaluation criteria.