The snowball texture in quartz and K_feldspar phenocrysts is commonly observed in some Li-F enriched and raremetal_bearing granites. The characteristics of its occurrence, the electron microprobe analyses of albite in snowball texture and other evidence indicate its genesis of magma crystallization differentiation. Based on the study of mineral crystallization sequence, solidus temperature and growth rates of quartz and albite, it suggests that Li-F-Na enriched granitic residual magma is qualified for the formation of snowball texture, and that high-ratio of Na2O/K2O and contents of F and H2O in the granitic melt are important to the formation of snowball texture. The increase of fluorine content might result in the drop of solidus temperature, thereby magma might be sufficiently differentiated, and K-feldspar and albite of near end-member compositions are formed. The high-ratio of Na2O/K2O leads albite to be crystallized firstly. The higher F and H2O contents might decrease viscosity of magma and increase the growth rate of quartz. Consequently, the albite might be wrapped by quartz phenocrysts and finally the snowball texture formed.