Abstract: Objective Owing to possible DNA breakage and degradation,tissues fixed by 10% neutral formalin may not be suitable for long-term preservation and downstream long DNA fragment amplification.This study aimed to compare the DNA quality extracted from lung cancer samples fixed by 70% ethanol versus neutral formalin.Methods Thirty cases of lung cancer tissues by 70% ethanol fixation(10 of which were collected by long time fixation more than 7 days)and 30 cases of formalin fixed samples were subject to DNA extraction with “Tissue/Cell DNA Extract kit”.Then DNA yields and purity were analyzed by agarose gel electrophoresis.Different length of expected DNA fragments of genes HBB(beta hemaglobin)and SERPINA9(antitrypsin)were amplified by common PCR and real-time quantitative PCR.Yields of PCR products were also compared by agarose gel electrophoresis.Results The integrity of DNAs extracted in 70% ethanol tissues was good without observed degradation,while DNAs from 10% formalin samples showed obvious smear bands during electrophoresis.Following common PCR,both yields of expected bands of 268bp and 536bp were more seen in group of 70% ethanol than in formalin group.By real time qPCR,all three amplicons of 100 bp,250bp and 350bp were more produced and shown at lower Ct values in 70% ethanol group compared with formalin group(P＜0.01).The success rate of qPCR for 346bp amplicons in formalin group samples was only 47%(14/30).DNA templates of antitrypsin were not significantly influenced by duration of ethanol fixation.Conclusion Quality of DNAs from 70% ethanol-fixed specimens was superior to formalin-fixed samples and suitable for long fragment amplification.Ethanol-fixed samples may be also suitable for long time transportation without compromising the DNA quality.