Abstract: Objective To study the effects of positive acceleration (+ Gz) on CGRP-mRNA in gastric mucosal and gastric mucosal blood fow of rats with experimental gastric ulcer and the related mechanism of the effect on ulcer healing. Methods Forty male SD rats were randomly and equally divided into four groups. Rats in group A was the normal control group without exposure to constant + Gz. The gastric ulcer was induced with acetic acid in rats of group B, C, D. After 3 d, rats in group B were bound on the ground for 5 min (exposure of constant + 1 Gz). Accordingly, the rats of group C and D were respectively exposed to + 5 Gz and + 10 Gz for 5 min (once every other day, 4 times in all). After 1 week, GMBF of rats which were anesthetized and fxed frstly was measured with the MoorVMS-LDF2 laser doppler blood fow meter. Gastric mucosa were collected to determinate quantitatively CGRP-mRNA in gastric mucosal by fuorescence quantitative PCR. Results The content of CGRP-mRNA of rats in group B (3.090±0.154) was higher than that in group A (0.966±0.089, P< 0.05). After exposure to + Gz, the content of CGRP-mRNA of rats in group B> group C (2.262±0.116)> group D (1.096±0.077), and all differences were statistically signifcant (P< 0.05). For the content of GMBF, group A (432.919±11.598) pU> group B (367.602±10.133) pU> group C (303.925±16.417) pU> group D (246.750±22.815) pU. The differences were statistically signifcant (P< 0.05). The content of CGRP-mRNA and GMBF in gastric mucosal of rats (rats in group B, C, D) with gastric ulcer had positive correlation after exposure to different +Gz (r=0.807, P< 0.05). Conclusion + Gz exposure delays gastric ulcer healing of rats, which may be related to the reduction of GMBF and alteration in the expression of CGRP – mRNA after exposure to + Gz.