It　was　hypothesized　that　the　microcirculatory　resistance　of　resting　state　(Rm-res)　might　be　a　good　predictor　for　ischemia.　In　this　study,　the　quantitative　relationship　between　Rm-res　and　myocardial　ischemia　in　different　stenosed　degrees　was　explored　and　verified　through　retrospective　analysis,　and　the　diagnostic　performance　was　evaluated.　136　patients　were　screened　and　divided　into　a　training　set　(90　patients)　and　a　validation　set　(46　patients).　In　the　training　set,　Rm-res　was　calculated,　and　thresholds　were　determined　by　exploring　the　relationship　between　Rm-res　and　myocardial　ischemia　in　different　stenosed　degrees.　In　the　validation　set,　the　diagnostic　performance　of　the　thresholds　was　verified.　It　was　found　that　the　90　data　mean　difference　(95%CI)　of　Rm-res　between　the　ischemic　group　and　the　non-ischemic　group　was　63.03　(95　%CI:　25.72-100.34),　p　＜　0.05.　In　the　training　set　with　stenosed　degree　41-60%,　61-70%,　71-80%,　and　＞　81%,　the　average　of　Rm-res　in　the　ischemic　and　non-ischemic　groups　were　(80.79,　136.87),　(96.41,　172.62),　(128.99,　198.94)　and　(175.95,　310.79)　mmHg/　s/ml.　The　Rm-res　thresholds　were　87.18,　118.96,　142.35,　and　177.39　mmHg/s/ml.　In　the　validation　set,　the　overall　sensitivity,　specificity,　PPV,　NPV,　and　accuracy　were　73.3%,　77.4%,　61.1%,　85.7%,　and　76.1%.　In　conclusion,　Rm-res　had　a　significant　predictor　on　myocardial　ischemia.　As　a　smaller　Rm-res　represents　greater　myocardial　mass　perfusion,　it　is　more　likely　that　a　stenosis　will　have　a　functional　impact.　Threshold　analysis　showed　that　Rm-res　of　different　stenosed　degrees　was　a　quantitative　predictor　of　myocardial　ischemia,　which　could　assist　physicians　with　clinical　treatment　strategies.