137 pathologically proved non-small cell lung cell patients were treated with thoracic three-dimensional conformal radiotherapy from the First Affiliated Hospital of China Medical University district between December 2009 and December 2011. The tumor was measured in pre-radiotherapy and radiotherapy 20 times to estimate the ratio of tumor decreased size. DNA was extracted by phenol-chloroform method from blood samples. Genetic single-nucleotide polymorphisms were divided by Taqman real-time PCR. All statistical analyses were performed with SPSS13.0. p<0.05 was confirmed statistically significant. T-test and analysis of variance were used to compare the data. Among the 137 patients, the average age was 60.1±5.33; the average ratio of tumor decreased size was 0.3474±0.191; squamous carcinoma were 87 cases; adenocarcinoma were 50 cases; male were 102 cases, while female were 35 cases;Ⅰstage were 9 cases,Ⅱstage were 26 cases, Ⅲ stage were 70 cases, and Ⅳstage were 32 cases; Smoking patient were 95 cases. The ratio of tumor-decreased-size of smoking patient was higher than that of no-smoking, respective 0.3755±0.1775 and 0.2840±0.2068, t=2.643, p=0.009. The ratio of tumor decreased size of LIG4rs1805388CC, CT and TT genotype were 0.3395±0.1802, 0.342±0.2106 and 0.5038±0.1892, respectively. The ratio of tumor-decreased-size of LIG4rs1805388TT genotype was higher than that of CC genotype through LSD method. There was no relationship between genetic single-nucleotide polymorphisms of HSPB1 and the ratio of tumor-decreased-size by radiotherapy in non-small cell lung cancer. The ratio of tumor-decreased-size by radiotherapy of smoking and LIG4rs180538TT genotype was higher than that of other patients.Cited