Lung cancer is one of the most common cancers in the world. Some genetic alterations such as p53 gene and ras gene mutations, have been identified in this disease. Recently, a putative tumor suppressor gene, the p16/CDKN2/MTS1 gene containing 3 extrons and 2 introns, located in the chromosome p21 region, was cloned independently by three research groups. Traditionally, gene mutation analysis was performed by slab polyacrylamide gel electrophoresis. However, this method is laborious, time-consuming, low sensitivity and harmful to human health. Capillary electrophoresis (CE) with the characteristics of rapidity and high performance has numerous advantages over conventional slab polyacrylamide gel electrophoresis. An important advantage of CE is that the commercially available system is automation.