The eighth root of 8 belongs to rational number. The specific reasons are as follows: First, integers and fractions are collectively called rational numbers. Wherein integers include positive integers, 0 and negative integers, and fractions include positive and negative fractions; Irrational numbers are infinite acyclic decimals, including numbers that cannot be opened by the root, numbers containing zeta, and infinite acyclic decimals. Secondly, the cube root of eight is actually equal to 2, so the cube root of eight belongs to a rational number.