Inthispaper,researchofaftershockmechanismsisreviewed,includingheterogeneityofmediumandstress,mechanicalloading,fluidintrusionandstresscorrosion,andratestatedependence.Previousstudieshaveindicatedthattheheterogeneityofmediaandstressisthebasicpremiseofaftershocksgenerated.Fromthepointviewofmechanics,transientcreepandafterslipcanexplainthedecayofaftershocksinashorttimeafteramainshockandtherelaxationofstresstendstointerpretthecharacteristicsoflong-termaftershocks.Fluidintrusionandstresscorrosioncontroltheevolutionprocessoftheaftershocksundercertainconditions.Theinteractionbetweenthefaultsperturbedbythemainshockalwaysexistsduringtheaftershockactivities.Allkindsofmodelsandthetheorieswanttocomplywiththetwobasicpower-lawrelationships---theG-RlawandOmorilawtosomeextent.
