The magnetic susceptibility in the Chinese loess is considered to have recorded thehistory of pedogenesis or land-surface stability, and has thus been used as an acute proxy of thesummer monsoon intensity. With regard to pedogenesis, most authors failed to appreciate thecomplexity of weathering processes. Specifically, not acknowledged are local redox conditions,carbonate concentration and leaching. Pre-depositional pedogenesis may be another factorundermining the legitimacy of using the susceptibility as an acute proxy of the summer monsoonintensity. These factors may not necessarily reflect the degree of pedogenesis although they havedefinitely affected the susceptibility signature. Some contributors to the susceptibility aredemonstrated to be inorganic iron and other organically complexed iron. The organic ironassociated with decomposed plant litter is proven to be the most important contributor to thesusceptibility in modern loess. But, magnetotactic bacteria are believed to be the major generatorsof the ultrafine ferromagnetic particles responsible for the susceptibility signature in theQuaternary loess and paleosols. The factors affecting susceptibility signature may well be site- andtime-dependent even within the Chinese Loess Plateau. Therefore, a more comprehensive modeland a more comprehensive approach are needed to address the relationship between thepaleoclimate and the proxy. The magnetic susceptibility in the Chinese loess is considered to have recorded the history of pedogenesis or land-surface stability, and has thus been used as an acute proxy of thesummer monsoon intensity. With regard to pedogenesis, most authors failed to appreciate the complexity of weathering processes. Specifically, not acknowledged are local redox conditions, carbonate concentration and leaching. These factors may not yet reflect the degree of pedogenesis although they havedefinitely affected the susceptibility signature. Some contributors are the susceptibility aredemonstrated to be inorganic iron and other organically complexed iron. The organic ironassociated with decomposed plant litter is proven to be the most important contributor to the susceptibility in modern loess. But, magnetotactic bacteria are believed to be the major generators of the ultrafine ferromagnetic particles responsible for the susceptibility signature in the Quaternary loess and paleosols. The factors affecting susceptibility signature may well be site- and time-dependent even within the Chinese Loess Plateau. Therefore, a more comprehensive modeland a more comprehensive approach are needed to address the relationship between thepaleoclimate and the proxy.