Abstract: Objective To assess the use value of ¹⁸F-FDG PET-CT in non-small cell lung cancer. Metheds (1) The CT and PET-CT image of 32 cases non-small cell lung cancer caseswere compared in staging. (2) The relativety between tumor size and SUV_max was observed. (3) Thirty cases with accepted therapy were compared to find the differences of remains and new outbreak lesions.Results (1) Seven cases were upstaged and 7 cases were downstaged.Changing rate in staging by PET-CT Was 43.8% (14/32).The difference of altered stage lymph node and metastasis in number was not in statistical significance by ¹⁸F-FDG PET-CT. (2) Spearman grade correlation coefficient r_a was 0.426.There were positive correlation between SUV_max and the tumor size (P<0.05). (3) PET-CT found 3 more remain lesions (Z=-0.520,P>0.05) and 19 mole new outbreak lesion (Z=-2.87 1,P<0.05) than that of CT.Conclusion ¹⁸F-FDG PET-CT had superiority in determining staging of non-small cell lung cancer,and was conducive in cheaking new outbreak lesions of accepted therapy eases.