抽象代数中，幂结合性是弱结合律。

如果由任意元素所产生的次代数符合结合律，这个代数就是拥有幂结合性。元素x能够多次自乘并不在乎到达了什幺幂数。例如x(x(xx)) = (x(xx))x = (xx)(xx). 以下结合律方式更为强烈：

代数中每个x, (xx)x = x(xx)

每个结合性的代数都明显地拥有幂结合性，一些交错代数（例如八元数）甚至是一些非交错代数（例如十六元数）亦如此。

In abstract algebra, power associativity is a property of a binary operation which is a weak form of associativity.

An algebra (or more generally a magma) is said to be power-associative if the subalgebra generated by any element is associative. Concretely, this means that if an element x is multiplied by itself several times, it doesn't matter in which order the multiplications are carried out, so for instance x(x(xx)) = (x(xx))x = (xx)(xx).