Special attention has been paid to the organic afterglow materials (OAM) for their fascinating properties.However,poor stability at air and complicated structure design hinder the development of OAM.Herein,sol-gel,a facile and simple technique,is employed to synthesize a series of organic/inorganic hybrid nanocomposites (N1/SiO2,N2/SiO2,and N3/SiO2) by covalently linking three common aryl imides with crosslinked silica skeleton.These nanomaterials show excitation wavelength-dependent and colorful (yellow,red and green) afterglow of organic imides with long lifetime up to 1.1 s at air.Interestingly,the ultralong phosphorescenceis ultrastable under various conditions:water,high temperature,UV irradiation and in vivo,due to the protection of inorganic silica.In particularly,heating to 500 ℃C does not quench the afterglow of organic luminophore in nanocomposites,but forms new ultralong phosphorescence originated from space-conjugation of silica and carbonyl.The afterglow nanomaterials display huge advantages in the applications of advanced anti-counterfeiting and bioimaging.