Mitochondrial tRNASer(UCN) gene mutation is closely related to acoustic nerve deafness. Some mutations can affect the structure and transcriptional processing of tRNASer(UCN), for instance m.7444G>A mutation in tRNASer(UCN) precursor 3' side, m.7472 insC as well as m.7511T>C mutations in the stem and ring of tRNASer(UCN), may influence tRNASer(UCN) stability, thus affect the synthesis of mitochondrial peptides, reduce the production of ATP and cause deafness. This article focuses on mitochondrial tRNASer(UCN) gene mutations as well as the mechanism underlying hearing loss.