Electronic Journal of Differential Equations, Vol. 2023 (2023), No. 41, pp. 1-29. Title: Space-time decay rates of a two-phase flow model with magnetic field in R^3 Authors: Qin Ye (Guangxi Normal Univ., Guilin, Guangxi, China) Yinghui Zhang (Guangxi Normal Univ., Guilin, Guangxi, China) Abstract: We investigate the space-time decay rates of strong solution to a two-phase flow model with magnetic field in the whole space $\mathbb{R}^3 $. Based on the temporal decay results by Xiao [24] we show that for any integer $\ell\geq 3$, the space-time decay rate of $k(0\leq k \leq \ell)$-order spatial derivative of the strong solution in the weighted Lebesgue space $ L_\gamma^2 $ is $t^{-\frac{3}{4}-\frac{k}{2}+\gamma}$. Moreover, we prove that the space-time decay rate of $k(0\leq k \leq \ell-2)$-order spatial derivative of the difference between two velocities of the fluid in the weighted Lebesgue space $ L_\gamma^2 $ is $t^{-\frac{5}{4}-\frac{k}{2}+\gamma}$, which is faster than ones of the two velocities themselves. Submitted September 21, 2022. Published June 23, 2023. Math Subject Classifications: 35Q31, 35K65, 76N10. Key Words: Compressible Euler equations; Two-phase flow model; Space-time decay rate; Weighted Sobolev space.