This kit uses the A-tailing method to synthesize the first-strand cDNA of miRNA. The miRNA Enzyme Mix contains E. coli Poly(A) polymerase, RTase, and RNase inhibitor. E. coli Poly(A) Polymerase not only has a high efficiency of A-tailing, but also specifically recognizes single-stranded miRNAs, thus avoiding further reverse transcription of miRNA precursors with double-stranded structures. The 2×miRNA RT Mix in this product contains all the ingredients and primers required for miRNA tailing and reverse transcription reactions, and has been optimized to ensure that the Poly(A) modification and reverse transcription processes at the 3' end of miRNA are performed efficiently at the same time. Combined with the universal reverse primers in the kit, subsequent qPCR only requires the design of specific forward primers to detect the miRNA in the sample.