GaN-based　green　light　emitting　diodes　was　designed　and　fabricated.　We　calculated　the　internal　electric　field　using　the　coupled　method　on　the　basis　of　analyzing　the　effect　of　the　spontaneous　polarization　and　the　piezoelectric　polarization.　Taking　into　consideration　of　the　effect　of　non-uniform　carrier　distribution　in　the　active　region,　we　obtained　the　fractions　of　the　carriers　and　the　rate　of　the　recombination　in　different　wells　by　calculating　the　steady　state　rate　equation　and　Poisson　equation.　It　was　found　that　the　calculation　data　are　consistent　with　the　experimental　data　for　the　changes　of　the　peak　wavelength,　the　light　power　and　the　halfwidth　with　the　current　in　the　range　of　10-70　mA.