Abstract: Objective To study the effect of dipyridamole on activation of platelets in dogs with open abdominal wound after seawater immersion. Methods Twelve dogs with open abdomen wound were randomly divided into general treatment group（n=6） and dipyridamole treatment group（n=6）.After seawater immersion,dogs in general treatment group received normal first-aid treatment while those in dipyridamole treatment group received dipyridamole infusion and normal first-aid treatment.Blood 5-hydroxytryptamine level was measured and platelet aggregation rate was detected. Results The blood 5-hydroxytryptamine level was higher while the platelet aggregation rate was lower in dipyridamole treatment group than in general treatment group. Conclusion Dipyridamole can effectively decrease the platelet aggregation rate but not the blood 5-hydroxytryptamine level in dogs with open abdominal wound after seawater immersion.