Objective To establish an animal model of inflammatory pleural effusion.Methods Forty guinea pigs were divided into two groups: experimental group with 7 subgroups and control group. In the experimental group the right chest cavity of each guinea pig was injected with 0.8～1.0 ml of 1% carrageenan, and guinea pigs of each subgroup were killed and observed respectively on day 1, 2, 3, 5, 7, 10 and day 14 after injection.Results Occurring on day 1(within 24 hours), pleural effusion reached the maximum on day 2～3 after injection, so did the neutrophil count in pleural effusion and inflammation of both pleura and lungs and then gradually decreased. The fibrosis and adhesion of pleura appeared on day 7 and were obvious on day 10. The encysted pleurisy was formed on day 14.Conclusion The carrageenan is an ideal pleural inflammatory inducer. This animal model is useful for studying pleural effusion. Objective To establish an animal model of inflammatory pleural effusion. Methods Forty guinea pigs were divided into two groups: experimental group with 7 subgroups and control group. In the experimental group the right chest cavity of each guinea pig was injected with 0.8-1.0 ml of 1% carrageenan, and guinea pigs of each subgroup were killed and observed respectively on day 1, 2, 3, 5, 7, 10 and day 14 after injection. Results Occurring on day 1 (within 24 hours), pleural effusion reached the maximum on day 2 ~ 3 after injection, so did the neutrophil count in pleural effusion and inflammation of both pleura and lungs and then gradually decreased. The fibrosis and adhesion of pleura had on day 7 and were obvious on day 10. The encysted pleurisy was formed on day 14.Conclusion The carrageenan is an ideal pleural inflammatory inducer. This animal model is useful for studying pleural effusion.