MicroRNAs are a class of important post-transcriptional regulators of gene expression in animals and plants. The intensive studies on differential expression and regulatory roles of microRNAs call for sensitive and specific method to detect trace amount of these small size, high sequence homological microRNAs. Here, a simple and reliable method for the quantification of microRNAs was presented. The hybridization products of target microRNAs with biotin-labeled capture probe and oligonucleotides-functioned gold nanoparticles probe were immobilized onto the surface of streptavidin-coated microplate, and the absorbance signals of gold nanoparticles were amplified by silver enhancement. Distribution of miR-122a/miR-128 in mouse brain and liver tissue were detected by this method, and then synthetic miRNA122a was quantified. Results show a lower detect limit of 10 fmol/L with a linear dynamic range from 10 pmol/L to 10 fmol/L and a high specificity to discriminate one single oligonucleotide mismatch of the target microRNAs.