High　performance　ion　exchange　chromatography　coupled　with　laser　light　scattering　instrument　was　employed　for　the　rapid　separation　and　quantitation　of　Ralstonia　solanacearum　of　different　virulences.　The　pure　culture　of　Ralstonia　solanacearum　was　successfully　separated　into　three　characteristic　fractions.　Each　fraction　was　collected　and　inoculated　onto　2,　3,　5-triphenyltetrazolium　chloride　(TTC)　plates　to　identify　its　virulence.　The　shapes　and　colors　of　the　colonies　were　imaged,　and　the　average　attenuation　index　(attenuation　index　=　red　spot　diameter　of　colony　/　total　colony　diameter)　of　ten　colonies　of　each　fraction　was　carefully　determined.　Furthermore,　each　fraction　was　inoculated　into　SPA　liquid　media　at　30　°C　with　shaking　(200　r/min)　for　48　h,　the　cells　were　harvested,　suspended　at　a　density　of　1.2　×　109　cfu/mL,　and　applied　to　infect　tomato　tissue　culture　plantlets　using　leaf-cutting　method.　The　infection　mortality　of　the　tomato　tissue　culture　plantlets　was　recorded　from　1　to　9　days　after　inoculation.　The　results　showed　that　the　virulences　of　each　fraction　were　different　on　the　basis　of　attenuation　index　and　infection　mortality.　The　virulence　of　peak　3　fraction　was　the　strongest　and　that　of　peak　1　fraction　was　the　weakest.　In　addition,　the　linear　relationships　between　different　injection　volumes　(1-180　μL)　and　their　peak　areas　were　investigated.　The　linearity　was　good　within　the　range　of　the　bacterial　number　of　9　×　106　-9　×　108　(r　=　0.99).　This　method　can　be　potentially　used　as　a　novel　tool　for　the　rapid　separation　and　quantitation　of　Ralstonia　solanacearum　of　different　virulences.　©　2007　Chinese　Chemical　Society　and　Dalian　Institute　of　Chemical　Physics,　Chinese　Academy　of　Sciences.