A new cavity structure containing negative refractive index dielectric layer is introduced into microcarity organic light-emitting devices (MOLED). Based on the transfer matrix method,the reflectance spectrum,the relation between the reflectance and incident angles and the dependence of electric luminescence (EL) spectra on cavity thickness were analyzed and discussed. The results show that the new MOLED have broader reflection band and better angular property than that of ordinary MOLED,compared to the same structure MOLED containing positive refractive index dielectric layer. The cavity thickness has little effect on the EL spectrum. So the thickness of the MOLED can be very thin. The new structure is beneficial for improving the properties of the MOLED.