Multiferroic (Bi0.95La0.05)(Fe0.97Mn0.03)O3/CoFe2O4 and CoFe2O4/(Bi0.95La0.05)(Fe0.97Mn0.03)O3 double-layered thin films were prepared on Pt(111)/Ti/SiO2/Si(100) substrates via a chemical solution deposition method. In both the thin films, superior multiferroic properties were observed at room temperature. However, substantial enhancements in magnetic properties, such as saturated ferromagnetic hysteresis loop with large 2Mr (68.8 emu/cm3) and 2Hc (11.7 kOe), as well as moderate ferroelectric properties, such as 2Pr (58 mu C/cm2) with low leakage current density (4 x 10-9 A/cm2 at 100 kV/cm), were observed in the (Bi0.95La0.05)(Fe0.97Mn0.03)O3/CoFe2O4 at room temperature. Structural distortion, deformation of [(Fe, Mn)O6] oxygen octahedra, and superexchange interaction in the (Bi0.95La0.05)(Fe0.97Mn0.03)O3 are attributed to the enhanced properties.