Abstract: As a non-contact optical measurement method in solid mechanics, thedigital speckle correlation method (DSCM), or alternatively, digital imagecorrelation method (DICM), has become an accepted method for measuring the surfacedisplacements field and displacement gradients in materials owing to its outstandingfeatures. The validity of the method has been shown by many instances in the lasttwenty years. Research to date on the DSCM hasled to improvements in the theory, experimental techniquesand application practices. The theory is becoming increasinglysophisticated. Some modern mathematical theories and methods (such as wavelet transformtheory, genetic algorithms and artificial neural networks, etc) are being introducedinto the DSCM. The convergencespeed and the precision of the method is further improved. The application fieldsof the method are extending from general materialsto some novel materials, from macro-field to meso-field and even micro-field, fromgeneral to severe environmental conditions and from laboratoryconditions to engineering sites, etc. In this review article, the state-of-the-artof the technique is reviewed and illustrated by referenceto recent publications on the developments and applications of DSCM.Especially, the applications of the method in micro-scale measurementsand testing of mechanicalproperties of new materials are discussed in detail. Some conclusions andpotential developing fields of the method are given in the end.