Poly(spirobifluorene)s (PSFs) are considered as the most promising blue emitters because they have better spectral stability than polyfluorenes (PFs).On one hand,the aggregation in the solid state is avoided effectively due to the orthogonal configuration between backbone and side groups.On the other hand,the spiro linkage at the 9-position of fluorene can prevent the possibility of the fluorene repeat unit into fluorenone,and further enhance their chemical stability.