采用动态激光光散射研究聚（苯乙烯－异成二烯）（ＰＳ－ＰＩ）二嵌段共聚物在选择性溶剂二氧六环／甲醇混合体系中微胶束的形成过程。讨论了温度、混合溶剂的组成和共聚物分子量对形成微胶束的影响。并对与体积排斥色谱法得到结果的差异进行了讨论，从而提出临界接触浓度的概念。还就实验测得的分子链尺寸和微胶束尺寸进行理论估算，结果符合Ｆｌｏｒｙ无扰链模型。 Dynamic laser light scattering was used to study the formation of micelles in a selective solvent mixture of dioxane and methanol with poly (styrene-isoprene) (PS-PI) diblock copolymer. The effects of temperature, composition of mixed solvent and copolymer molecular weight on micelle formation were discussed. The differences between the two methods were also discussed. The concept of critical contact concentration was put forward. The molecular chain size and micelle size measured by the experiment were also estimated theoretically. The results accord with the Flory chainless model.