Inserting a $SiO_2$ layer underneath the p-pad electrode as the current blocking layer (CBL) structure and extending p-metal finger patterns, the GaN LEDs using an indium-tin-oxide (ITO) layer show the improved light output intensity, resulting from better current spreading and reduced light loss on the surface of p-pad metal. The LEDs with an oxide layer of $100{mu}m$-pad-width and $6{mu}m$-finger-width have better light output intensities than those with an oxide layer of $105{mu}m$-pad-width and $12{mu}m$-finger-width. Using the ATLAS device simulator from Silvaco Corporation, the current density distributions on the active layer in CBL LEDs have been investigated.