Abstract: Objective：To establish an ELISA-based method to detect IgG antibody against Aspergillus fumigatus thioredoxin reductase GliT (TRG) and estimate the diagnostic value of anti-TRG antibody for invasive aspergillosis (IA). Methods：In this study 42 non-agranulocytosis patients and 34 agranulocytosis patients were included. The control sera were obtained from healthy individuals (n=200) and non-IA patients with infections of other fungi or bacteria documented by blood culture. An ELISA method for detection of anti-TRG antibody levels in sera was set up using the recombinant TRG as coating antigen. The anti-TRG antibody levels in sera of IA patients were detected by ELISA. The sensitivity and specificity of the assay were compared with GM test. A rabbit IA model was used to estimate the antibody response of TRG. Results：The cutoff value of the ELISA was 0.514. In non-agranulocytosis IA patients, the median absorbance value of anti-TRG antibody was 0.827 (interquartile range 0.571-1.234), and the sensitivity was 81.0% (34/42). In agranulocytosis IA patients, the median absorbance value of anti-TRG antibody was 0.445 (interquartile range 0.250-0.924), and the sensitivity was 41.2% (14/34). The median absorbance value of anti-TRG antibody in IA patients was significantly higher than that of non-IA patients or healthy individuals (P<0.01). In non-agranulocytosis IA patients, the sensitivity of the anti-TRG antibody test for diagnosing IA (81.0%) was superior to GM assay (52.3%) (P<0.01), while in agranulocytosis IA patients GM assay was superior to anti-TRG antibody test (P<0.01). By combining GM assay with anti-TRG ELISA, the diagnostic sensitivity for non-agranulocytosis and agranulocytosis patients increased to 88.1% (37/42) and 91.2% (31/34) respectively. The kinetic analysis for anti-TRG antibody level showed a constant rise in the early stage of IA, and then fell to normal level if the patient responded to anti-fungal therapy. The anti-TRG antibody in the serum of rabbit IA model was detectable on the 7 day after infection with Aspergillus fumigatus and the antibody level increased constantly. Conclusion：The anti-TRG antibody should be a potential marker for auxiliary diagnosis of IA in non-agranulocytosis patients.