It was proved that split injection strategy could improve power in DISI engines with stoichiometric or rich mixtures under full load condition. This study investigated whether split injection strategy could achieve power improvements in DISI engines with lean mixtures. The effects of 1st injectontiming,2nd injection timing, and fuel split ratio were investigated The relations between combustion characteristic and exhaust emissions were considered. The results showed that split injection strategy could improve power in DISI engines with lean mixtures.