Thirteen strains isolated from diseased materials of 11 citrus varieties collected from Beihai and Guilin districts were studied.Among 35 physiological characteristics assayed in 13 strains,25 items including citrate,malonate,growth at 36℃,NaCl tolerance,Tween 20,Tween 80,salicin,dulcitol,glucose,lactose,cellubiose,phenylalanine,raffinose,melezitose,adonitol,synanthrin,ribose,mannitol,arabinose,trehalose,melibiose,sorbitol,aesculin,tartrate,gelatin were identical and 10 items including acetate,D-fructose,valerate,rhamnose,xylose,sucrose,maltose,galactose,starch,mannose were different; 12 items including cytochrome C oxidase,catalase,MR,VP,hydrolysis of aesculin,production of levan,reduction of nitrate,production of urease,phenylalanine,arginine dihydrolase,lecithinase,hydrolysis of gelatin identical and 4 items including hydrolysis of starch,production of indole,production of H2S,litmus milk different among 16 biochemical ones in strains.The 13 strains could be differentiated by their sensitivities to 3 phages and be divided into 6 types,while no difference could be detected among the strains by the fatty acid profiles.