Abstract: The choice of partners during organizing a dynamic alliance of corporations is so important that it will decide whether the alliance meets with success. Differing from what was emphasized in earlier works where the high risk due to improper choice of alliance partners and risk precontrol had not been taken into account, the principle and criterion of choice of alliance partners are put forward in a risk prevention perspective. In the assessment/choice process of alliance partners, a corporation's core competence, risk sustainability and project flexibility are all included. The procedure and practice of multi-stage choice of alliance partners are set out with a numerical example.