Recently, the outbreak of Type A Influenza such as Avian Influenza and Swine Influenza brings serious threat to human health. However, the current anti-influenza A virus (IAV) drugs are easy to produce virus resistance and have many side effects, so it is necessary to research and development novel natural anti-IAV drugs with low toxicity and high efficiency.. The good anti-viral effect of carrageenanis at(?)acting increasing interest all over the world, and carrageenan has unignorable potential(?) the deve...