The solidification structure of twin-roller continuous casting pure aluminum was predicted by a 3D cellular automaton （CA）-finite element （FE） model. In the present CA-FE model

Gaussian distribution of nucleation sites was adopted both at the roll surface and in the melt. Then the modified Kurz-Giovanola-Triedi（KGT） model was used to describe the growth kinetics of dendrite tip. Simulated results show that the grain growth in random preferential growth directions can be described by the model reasonably

and the simulated results are coincident with actual phenomena in temperature field

solute field and microstructure evolution. By use of the model

the effects of process and solidification parameters on the solidification structure of grain zone were understood. The results show that the width of columnar grain zone is increased with increasing in roll surface heat transfer coefficient

while it is decreased with the increase of inner max nucleation density

and fine and uniformly distributed grain in the solidification structure can be observed.