OBJECTIVE： To study the gene mutation status of epidermal growth factor receptor （EGFR） in non-small cell lung cancer （NSCLC） patients and its relationship with clinical indexes， and to provide reference for individualized administration of EGFR-TKI in NSCLC patients. METHODS： Totally of 274 NSCLC patients from the northern of Jiangsu area were selected from our hospital during Jan. 2015-Dec. 2017. Mutation status of EGFR gene in lung tissue was determined by amplification refractory mutation system （ARMS）-TaqMan PCR assay. The relationship of EGFR gene mutation with clinical indexes as gender， age， smoking status， staging， tumor differentiation and pathological type were analyzed retrospectively. Compared with related literatures， the regional differences of EGFR gene mutation were analyzed. RESULTS： Among 274 NSCLC patients， 112 patients suffered from EGFR gene mutation with total mutation rate of 40.88％. There were 50， 57， 3， 2 cases of exon 19， exon 21， exon 20 and exon 19+21 mutation， and the types of EGFR gene mutation were delE746-A750， L858R and insH773-V774H， etc. The mutation rates of EGFR gene exon 19， exon 21 in non-smoking， early， well-differentiated and adenocarcinoma patients were 52.50％， 47.24％， 46.36％ and 45.00％， which were significantly higher than smoking （28.57％）， advanced （27.03％）， poor-differentiated （31.71％） and squamous cell carcinoma （27.66％） patients， with statistical significance （P＜0.05）. There was no statistical significance in mutation rates of EGFR gene exon 19 and exon 21 between male and female， ≥65 year-old and ＜65 year-old patients （P＞0.05）. EGFR mutation rate of NSCLC subjects from the northern of Jiangsu area was significantly higher than Shanghai area （P＜0.05）； there was no statistical significance compared with Yunnan area （P＞0.05） but mutation types were different. CONCLUSIONS： There is the highest EGFR gene mutation rate in its exon 21， lesser in exon 19， rare in exon 20 and exon 19+21 among NSCLC patients from the Northern of Jiangsu area. There are obvious regional differences. The mutation rate of EGFR gene mutation exon 19 and exon 21 are associated with smoking status， staging， tumor differentiation and pathological type of NSCLC patients. The non-smoking， early stage， well-differentiated and adenocarcinoma patients are more likely to benefit from EGFR-TKI targeted therapy.