Objective To investigate the significance of metastasis associated lung adenocarcinoma transcript 1 (MALAT1) in the occurrence and development of non-small cell lung cancer(NSCLC).Methods Eighty-six NSCLC lung tissue samples and 86 corresponding adjacent tissues were collected.Real-time quantitative polymerase chain reaction (RT-PCR) was used to detect MALAT1 mRNA expression.The correlation analysis of the gender,age,carcinoma embryonic antigen (CEA),clinical stage,and the degree of differentiation was performed.Results MALAT1 expression levels showed an average 2.16-fold increase in NSCLC lung tissues(87.23 ±9.72) when compared with adjacent tissues(40.38 ± 5.49),the difference was statistically significant (t =7.894,P ＜ 0.01).There was no significant difference between gender,age,histological type,tumor diameter,CEA level in terms of MALAT1 expression (P ＞ 0.05).There was significant differences between pathological stage (Ⅰ stage =52.38％ (11/21),Ⅱ stage =76.00％ (19/25),Ⅲ stage =97.50％ (39/40),x2 =11.839,P =0.042),tumor differentiation (High differentiated =39.13％ (9/23),moderately differentiated =74.47％ (35/47),low differentiated =100％ (16/16),x2 =15.383,P =0.032)and lymph node metastasis (with =97.22％ (35/36),no =46.00％ (23/50),x2 =23.947,P =0.030).Conclusion MALAT1 might be involved in the development of NSCLC,and could be an auxiliary diagnosis marker.