Lung cancer is a leading cause of cancer death worldwide. The effectiveness of lung cancer targeted high-risk population using low dose chest computed tomography has been reported several randomized controlled trials. Thus, recently, lung cancer screening to high-risk group is recommended internationally. National Cancer Center reported a lung cancer screening guideline by evidence-based methods in 2015. Korean national lung cancer screening program started from 2019 after evaluation of Korean lung cancer screening demonstration project (K-LUCAS) nationwide. K-LUCAS obtained comparable high early lung cancer detection rate, lower false positive rate and lower complication rate compared with clinical trials conducted in other countries. Also psychological anxiety of screening participants had been low, but willingness of smoking cessation had been increased after screening. This paper will review the evidence of lung cancer screening from clinical trials, also, evaluate the benefits and harms of screening based on K-LUCAS.