For the power series distribution, generated by an entire function of finite order, we obtain the asymptotic behavior of its regularly varying moments. Namely, we prove that $E_wX^\alpha\ell(X)\sim(E_wX)^\alpha\ell(E_wX)$, $\alpha>0$ ($w\to\infty$), where $\ell(\cdot)$ is an arbitrary slowly varying function.