活性聚合反应在高分子化学中是一种链增长聚合反应，为了终止生长能力的聚合物链，而将它移除。 缺少链终止反应和链转移反应。链引发的速度比链扩展的速度来得大。就结果来说，聚合物链生长的速度比传统的链的速度还来得恒定，且他们链的长度是相似的。（即它们具有非常低的多分散性指数）。活性聚合反应对于共聚物是一种常用的聚合方法，由于可以分阶段进行合成，所以每个阶段都有不同的单体存在。另外的优点是可以预定莫耳质量及控制末端基团。

活性聚合反应: 缺少链转移及链终止的一条链

注: 在许多情况下, 链的起始反应速度比链的延长速度来得快
, 使动能链所带的能量在聚合反应中是稳定的。

In polymer chemistry, living polymerization is a form of chain growth polymerization where the ability of a growing polymer chain to terminate has been removed. This can be accomplished in a variety of ways. Chain termination and chain transfer reactions are absent and the rate of chain initiation is also much larger than the rate of chain propagation. The result is that the polymer chains grow at a more constant rate than seen in traditional chain polymerization and their lengths remain very similar (i.e. they have a very low polydispersity index). Living polymerization is a popular method for synthesizing block copolymers since the polymer can be synthesized in stages, each stage containing a different monomer. Additional advantages are predetermined molar mass and control over end-groups.