Abstract-Wet　ball-milling　and　rotating　synthesizing　have　been　combined　in　a　new　preparation　technology　of　cathode　material　LiNi0.5Co0.5O2　for　lithium　ion　battery.　The　raw　materials　can　be　perfectly　mixed　uniformly　with　a　uniform　granularity　distribution　using　wet　ball-milling.　XRD　results　show　that　the　prepared　LiNi0.5Coo.5O2　is　a　pure　material　with　α-NaFeO2　structure.　The　LiNi0.5　Coo.sO2　powder　have　homogeneous　chemical　composition　and　narrow　granularity　distribution.　The　temperature　.granularity,crystal　structure　and　chemical　composition　of　the　material　were　homogenous　during　rotating　synthesizing.　Electrochemical　property　tests　testify　that　LiNio.sCo0.5O2　powder　synthesized　under　the　optimum　conditions　have　an　initial　charge　capacity　of　173　mAh/g　and　discharge　capacity　of　148　mAh/g　for　charge/discharge　current　density　of　0.　2　mA/cm2　and　charge/discharge　voltage　of　3.　0V　and　4.　2V.　The　discharge　capacity　decays　to　130　mAh/g　or　so　after　30　cycles,indicating　a　good　cycle　stability.