Interactions　between　technology　progress　and　social　regulation　on　city　disaster　mitigation　and　prevention　are　studied　in　this　paper.　At　first,　we　review　technology　progress　and　social　regulation　mechanism.　Then　we　analyze　the　cost　and　return　on　city　disaster　mitigation　and　prevention.　We　find　that　technology　progress　and　social　regulation　are　interacting　on　each　other;　social　regulation　on　city　disaster　mitigation　and　prevention　is　the　product　of　technology　progress,　industrialization　and　urbanization;　technology　progress　improves　efficiency　of　social　regulation　on　city　disaster　mitigation　and　prevention.　We　also　bring　forward　some　reasonable　proposals　to　improve　the　efficiency　of　social　regulation　on　city　disaster　mitigation　and　prevention.　During　the　process　of　urbanization　in　China,　the　dynamic　social　regulation　system　on　city　disaster　mitigation　and　prevention　should　be　established　corresponding　with　technology　progress.