Objective To investigate the effects of Helicobacter pylori(H.pylori)infection on autonomic nervous function and calcitonin gene-related peptide in patients with functional dyspepsia(FD). Methods Thirty-one patients with FD matching Rome 鈪?criteria were included and divided into H.pylori-positive group and H.pylori-negative group.All patients were evaluated by Symptom Index of Dyspepsia(SID),Nepean Dyspepsia Index(NDI),and Hospital Anxiety and Depression Scale(HADS).Their heart rate variability(HRV)and calcitonin gene-related peptide(CGRP)level were also measured. Results There were no significant differences in SID(Z=-0.858, P=0.858),NDI(Z=-1.464, P=0.143),and Hospital Depression Scale score(Z=0.699, P=0.485).However,the Hospital Anxiety Scale score was significantly higher in H.pylori-positive group than the H.pylori-negative group(Z=-2.470, P=0.014).The level of CGRP in H.pylori-positive group[(0.999+/-0.274)ng/ml]was significantly higher than that in the H.pylori-negative group[(0.812+/-0.172)ng/ml;t=2.238, P=0.033].HRV data showed no significant difference between these two groups at very low frequency(t=-1.210, P=0.236),low frequency(LF)(t=0.419, P=0.678),high frequency(HF)(t=0.612, P=0.546),LF/HF(t=-0.882, P=0.399),and total power(t=-0.963, P=0.344). Conclusion In FD patients,patients with H.pylori-positive FD patients have higher depression and CGRP levels than those without H.pylori infection,although their dyspepsia symptoms and HRV show no notable changes.