Rectal distension (RD)induce upper GI symptoms. The aim of this study was to investigate the effects and mechanisms of RD on gastric slow waves ( GSW) and motor activity, to investigate the effects and mechanisms of electroacupuncture (EA) on GSW and motor activity. Methods: Eight female hound dogs implanted with gastric serosal electrodes and a gastric fistula were studied in six separate sessions. Antral motility, gastric slow waves, heart rate variability and rectal pressure were evaluated for above purposes. Results: 1) RD at a volume of 120ml suppressed antral motility significantly. Guanethidine blocked the inhibitory effect of RD. EA was able to restore the suppressed antral contraction induced by RD (16.6±1.7 vs. 8.0±1.4, p<0.001). Naloxone partially blocked the effect of EA on the antral contraction 2) RD reduced the percentage of normal GSW that was increased with EA. The effects of EA on the GSW were no longer observed at the presence of naloxone. 3) EA did not show any significant effect on rectal pressure, suggesting that the ameliorating effects of EA on RD-induced impaired gastric motility was not attributed to a decrease in rectal pressure. 4) EA increased the vagal activity suppressed by RD. Conclusions: RD inhibits postprandial gastric motility and impairs GSW in dogs, and the inhibitory effects are mediated via the adrenergic pathways. EA is able to restore the RD-induced impaired GSW and motor activities possibly by enhancing vagal activity, and partially mediated via the opioid pathway. EA may have a therapeutic potential for functional gastrointestinal disorders.