DNA Sequencing is one of the most important techniques in biology which determine precise order of nucleotides within a DNA molecule. Old methods such as Sanger DNA Sequencing, are time laboring and expensive methods. Therefore, researchers developed next generation Sequencing (NGS) which are more economical and high-throughput methods comparing with old methods. NGS methods classified into three main generations. These methods are able to fast Sequencing of long fragments of DNA. By means of NGS, whole genome Sequencing, target specific Sequencing, de-novo Sequencing and assembly, RNA Sequencing and investigation of genetically changes are possible. it's so important to consider befits and defects of each method, and choosing a suitable NGS method due to properties of research program.