The p53 mutations in the reported 243 lung cancers and our 59 cases were analyzed. The common base substitutions found in the lung cancer were G to T transversion (35%), C:G to T:A (26%) and A:T to G:C transitions (11%). Four types of the hot spot, 1) G to T transversion, 2) A to G transition in ApT site, 3) C to T transition in CpG site and 4) mix of the transversion and transition were identified. It is suggested that A to G transition at ApT site in the non-transcribed strand may be a new hot spot in the p53 gene in lung carcinoma. We also show that microscopic selection of cancer cells will facilitate the detection of p53 mutations in adenocarcinomas.