As　the　core　of　LED　light　source,　the　quality　of　LED　chip　directly　determines　the　performance,　life　and　so　on　of　the　device.　Therefore,　the　improvement　of　optical　extraction　efficiency　is　the　key　step　to　promote　the　development　of　LED　chip　technology　when　the　internal　quantum　efficiency　has　reached　a　fairly　high　level.　Due　to　the　insulating　property　of　sapphire,　the　N　and　P　electrodes　of　normal　LED　are　made　on　the　same　side　of　the　light　output　surface　of　the　chip.　The　P　metal　electrode　on　the　light　output　surface　absorbs　most　of　the　light　emitted　from　the　luminous　region　directly　below　it,　and　causes　light　loss.　To　improve　this　phenomenon　and　alleviate　the　current　crowding　around　the　P　electrode,　in　this　paper,　we　fabricated　LED　devices　with　SiO2　current　blocking　layer(CBL)　that　was　deposited　between　ITO　transparent　conductive　layer　and　P-GaN　,　and　another　kind　of　LED　without　CBL.　We　tested　voltage,light　output　power,　main　wavelength　of　the　two　kinds　of　chips　without　package　under　350mA　working　current.　The　results　showed　that　the　forward　voltage　of　the　two　kinds　of　chips　are　concentrated　in　3　similar　to　3.　1V,　while　the　light　output　power　of　the　LED　with　CBL　is　obviously　improved.　CBL　blocks　the　current　from　diffusing　below　the　P　electrode　and　reduces　the　current　density　flowing　to　the　active　region,　thus　reducing　the　absorption　and　shielding　of　light　by　the　P　electrode,　and　directing　the　current　to　the　region　far　away　from　the　P　electrode　through　CBL,　reducing　current　congestion　around　the　electrode.　Then　the　two　kinds　of　chips　were　packaged　in　the　same　package　structure　and　process　conditions.　The　thermal　characteristics　and　photoelectric　properties　of　two　samples　were　investigated　under　different　current　range　from　10　to　600　mA,　and　the　spectra　and　optical　power　of　two　kinds　of　devices　were　obtained.　Results　showed　that　main　wavelength　of　the　two　samples　blue　shift　with　the　increasing　current,　and　the　main　wavelength　blue-shifting　of　LED　with　CBL　is　10nm　less　than　the　LED　without　CBL.　It　can　be　seen　that　the　spectra　of　LED　inserted　CBL　is　less　affected　by　the　increasing　current.　Therefore,　its　color　rendering　properties　is　more　stable.　Under　the　low　current,　CBL　structure　has　little　effect　on　the　optical　power　of　the　device.　With　the　increase　of　current,　the　improvement　effect　of　CBL　on　the　optical　power　is　improved　gradually.　Under　the　heavy　current,　the　junction　temperature　of　the　LED　without　CBL　is　higher　and　the　forward　voltage　is　lower,　and　the　voltage　difference　between　the　two　kinds　of　devices　increases　with　the　increasing　current.　Under　25　degrees　C　ambient　temperature,　350　mA　working　current,　the　voltage　of　LED　with　CBL　increases　0.　04　V,　but　it　improves　optical　power,　the　highest　increase　is　9.　96　degrees　A　,　and　the　thermal　resistance　is　obviously　smaller　than　the　device　without　CBL　structure,　which　indicates　that　the　heat　production　of　LED　with　CBL　is　less　than　the　device　without　CBL　structure.　Therefore,　the　optical　extraction　efficiency　of　the　device　is　improved　by　CBL　structure.　And　the　spectrum　drifting　is　smaller　and　the　color　rendering　properties　is　more　stable.