Abstract: Lithium complex with 8-hydroxyquinoline was synthesized and purified,and its purity was examined,then the sample was analyzed with XRD and UV spectra before and after purification.The surface of the Liq film purified for different times with different techniques was observed with AFM,it is found that its property of luminescence and the surface roughness are improved after purification.The blue OLED with a ITO/PVK:TPD/Liq/Al structure is obtained,and its P-L,E-L spectra and its J-V,L-V curves are measured.The correlation between the surface morphology of Liq film and the luminescence property of the device was studied.