Influence of 4 kinds of superplasticizer(SP), i.e. polycarboxylate superplasticizer(PC), naphthalene sulphate based superplasticizer(NSF), melamine sulphate based superplasticizer(MSF) and aliphatic superplasticizer(SAF), on autogenous shrinkage(AS) of mortar in early age was studied by using the method of volumetric deformation measurement. The test results show that the 4 kinds of SP in various dosages can increase the AS. AS increases along with the increase of the addition amounts of NSF, MSF and SAF.It increases first and then falls with the dosage increase of PC. When mortars with SP are in the same fluidity, the capability of the SPs that increases the AS is in the following sequence(from strong to weak):NSF, SAF, MSF and PC. The pore size distribution of mortar is changed by superplasticizer is considered as the main way to affect AS.