MicroRNA is a small non-coding endogenous RNA molecule which is consisted of approximately 22 nucleotides. It degenerate target gene mRNA or suppress its protein translation through integration with the 3UTR of the target gene. MicroRNA regulates over 30% of protein coding genetic expression of the genome by cleavage and translation suppression. Keratinocyte cell proliferation and abnormal differentiation are the key characteristics of psoriasis, and these pathological changes are thought to originate from cell immune system. T cell, dendritic cell and multiple immune-related cell factors were all involved. MicroRNA participates in throughout the pathological process and plays an important role. MicroRNA expression specificity and sequence shows great similarity with the temporal-spatial characteristic of the syndrome. Introducing mircoRNA into psoriasis TCM syndrome research provides a new aspect to the topic through the interpretation of post-transcriptional level.