Abstract: Using the recursive method, the formula for the expected values of three types of Kirchhoff indices (Kirchhoff index, multiplicative degree-Kirchhoff index and additive degree-Kirchhoff index) in the random cyclooctane chains is first determined. Then the maximum and minimum values of three types of Kirchhoff indices among cyclooctane chains with n octagons (based on this formula) is obtained. All the corresponding extremal graphs are characterized.