Myelodysplastic syndromes（MDS） is originated from pluripotent hematopoietic stem/ progenitor cell with heterogeneity ma－lignancies and the pathogenesis is still obscure. Interstitial deletion of chromosome 5 is the most common cytogenetic abnormality in MDS and it is related with the pathogenesis of MDS. Furthermore，haploinsufficiency in RPS14，SPARC and the absence of mutations in miRNA，P53 were found in del（5q）MDS patients and RPS14 was proved to play the anti-oncogene role in the 5q-syndrome. This article summarized the newly released investigation of molecular pathogenesis associated with the development of MDS with del（5q）.