The Landau-Khalatnikov (LK) simulation was used to study magnetoelectric (ME) coupling phenomena in a composite system of magneto-strictive CoFe2O4 (CF) and piezoelectric BaTiO3 (BT) materials, CF-BT. By adding ME coupling term with coupling parameter gamma, between polarization, P and magnetization, M of gamma(PM2)-M-2 in thermodynamic free energy density functional for LK simulation, the hysteretic ME coupling coefficients, alpha(ME)(H) in CF-BT composite systems were well simulated and small changes of magnetic-field (H) dependent polarization, P(H) were calculated. The maximum values of alpha(ME) are proportional to gamma in the broad ranges of more than 7 orders of magnitude.