The main objective of this review is to describe the new sequencing technologies called next generation sequencing (NGS) and its utility as a molecular genetic diagnosis tool in a medical field. Sanger method has dominated the genome sequencing industry for the past 30 years since its invention in 1975. It produced first human genome and still remains the gold standard for genome sequencing. However, it cannot meet the needs for enormous genetic data gathering and process because of its relatively long sequencing time and high cost per sample. NGS which parallelise the sequencing process, thereby increasing processing speed at a reduced cost per sample emerged to compensate for the weakness of the previous method. Currently NGS is used in some medical areas and its use is being widened. NGS also plays an important role in a study of genetically heterogenous hearing diseases. NGS is expected to mark a significant milestone in genomic research filed in a near future.