Abstract: Objective:To investigate the value of CT texture analysis in the evaluation of response to gefitinib-based treatment in patients with lung adenocarcinoma. Materials and Methods:Twenty-one patients with lung adenocarcinoma who received a treatment of gefitinib were retrospectively analyzed, and were evaluated as partial response(PR) after 3 months treatment based on RECIST 1.1(Response Evaluation Criteria in Solid Tumors, Version 1.1). We obtained and compared the quantitative texture parameters of gray histograms and GLCM on CT scan images before and after 3 months of treatment, respectively. A subgroup analysis of progression-free survival(PFS) of no less than 1 year and less than 1 year, were conducted to compare the changes in texture parameters before and after treatment. Results:Twenty-one patients with lung adenocarcinoma were evaluated as PR after 3 months of treatment with gefitinib. There were significant decreases in the mean gray value, skewness, kurtosis and entropy of the lesions, while there were significant increases in the standard deviation, angular second moment, and inverse difference moment of the lesions after the treatment(P < 0.05). There was no significant difference in contrast between pre-and posttreatment(P > 0.05). A subgroup analysis of PFS showed a significant difference in Δ inverse between the two groups(P < 0.05). Conclusion:CT texture analysis may be helpful for the evaluation of short-term effect to gefitinib-based treatment and the prediction of PFS in patients with lung adenocarcinoma.