Influences of transverse DC static magnetic field on microstructure of Zn-35Al-2.5Cu-1.5Ti alloy were investigated by modified self-developed horizontal Bridgman directional solidification device. Influences of the magnetic field on the microstructure of the zinc alloy were investigated by observing the microstructure and its quantitative characterization. The results show that with increasing in magnetic induction intensity

the microstructure in the directional solidified Zn alloy is coarsened

which is attributed to the Thermo-Electric MagnetoHydroDynamic （TEMHD） effect generated from the presence of a magnetic field promoting the melt flow in the liquid-solid interface mushy zone and atomic migration. With increasing in drawing velocity

the microstructure is refined as a result of fading of TEMHD. The microstructure in zinc alloy becomes coarse seriously with the magnetic induction intensity of 0.2 T and drawing velocity of 30 μm/s. Compared with the absence of magnetic field

the first arm and the second arm spacing are increased by 44.9% and by 52.2%

respectively.