Tropical cyclones and extratropical explosive cyclones are the most hazard weather systems threatening the safety of ships at sea. It is a basic guarantee for safety management and economic benefits for the marine industry to avoid tropical cyclones and explosive cyclone safely and effectively and minimize their effects on ships. A technique of avoiding tropical cyclones based on the target circles for tropical cyclone track forecast is put forward on the basis of the experiences of ship navigation for avoiding tropical cyclones at sea in the past years. An example of successfully routing is presented with detailed explanation on the basic principles, procedures and key techniques. According to the statistical data on the utility assessment, this technique is of great value in ap plication. This technique also applies to cases for avoiding explosive cyclones for vessels.