Evaluation　index　system　and　grading　standard　for　urban　comprehensive　disaster　prevention　and　disaster　mitigation　capacity　were　established.　Then　taking　the　cities　as　basic　evaluation　units,　on　the　basis　of　variable　fuzzy　sets　theory,　the　corresponding　model　for　variable　fuzzy　assessment　was　established.　This　could　reasonably　identify　the　relative　membership　degree　between　the　index　of　assessment　unit　and　its　standard　interval.　So　we　can　properly　determine　the　comprehensive　assessment　grade　of　each　unit　by　varying　the　parameters　of　the　model.　Then　the　urban　disaster　hazard　grade　and　the　vulnerability　grade　were　calculated,　as　well　as　the　disaster-carrying　capacity　grade.　Based　on　the　three　results,　the　level　of　urban　comprehensive　disaster　prevention　and　mitigation　capability　was　established.　At　last　urban　comprehensive　disaster　prevention　and　mitigation　capacity　of　five　typical　was　evaluated,　the　results　were　consistent　with　the　results　of　other　method　and　that　proved　the　effectiveness　and　rationality　of　the　method.