The influence of rare earth lanthanum and pouring temperature on the fluidity of ADC 12 aluminum alloy was studied through spiral fluidity specimens by means of optical microscopy(OM)and differential thermal analyzer(DTA).The least squares regression method was used to give the best fitting between the function and the experimental data.The experimental results indicate that the rare earth lanthanum can significantly increase the fluidity of ADC12 alloy.The fluidity increases with the addition of lanthanum.The DTA results indicate that with the addition of lanthanum,the range of crystallization temperature decreases,which increases the fluidity length.Especially,the range of crys-tallization temperature decreases by 32.66％and the fluidity length is 1,321 mm(increased by 38.91％)when the addi-tion of lanthanum is 0.6 wt％.Furthermore,with the increase of pouring temperatures,the fluidity length increases linearly between 670 and 760℃.