Objective:　To　detect　the　blood　viscosity　values　and　find　out　the　statistically　significant　influencing　factors　of　blood　viscosity　and　their　fitting　formulas　among　the　middle-aged　and　elderly　people　with　high　incidence　of　cardiovascular　diseases.　Methods:　The　subjects＇　blood　was　collected　in　the　hospital,　together　with　their　physiological　and　pathological　information,　and　LG-R-80　series　rotary　viscometer　detector　was　used　to　detect　blood　viscosity.　The　statistically　significant　factors　of　blood　viscosity　and　their　fitting　formulas　were　obtained　by　using　SPSS.　Results:　Blood　viscosity　increased　with　age　and　body　mass　index　(BMI)　and　reached　its　peak　value　in　60　year-old　males　(5.35　mPa·s)　and　50　year-old　females　(4.45　mPa·s),　respectively,　then　the　variation　of　blood　viscosity　would　be　stabilized,　with　no　more　increase;　the　blood　viscosity　values　of　males　in　all　groups　with　different　ages　were　significantly　higher　than　those　of　females,　with　difference　value　in　the　range　of　0.28-0.90　mPa·s;　the　blood　viscosity　values　were　obviously　higher　in　hypertension　group　than　those　in　normal　group,　with　statistically　significant　differences　(P＜0.1).　Conclusions:　The　blood　viscosity　distribution　in　people　with　high　incidence　of　cardiovascular　diseases　has　certain　regular　pattern,　and　the　obtained　fitting　formula　between　blood　viscosity　and　influencing　factors　in　this　study　would　provide　useful　references　for　further　study　such　as　variation　of　blood　viscosity　under　different　physiological　conditions,　effects　of　different　viscosities　on　some　cardiovascular　diseases,　and　non-invasive　detection　of　blood　viscosities.　Copyright　©　2014　by　the　Editorial　Board　of　Journal　of　Medical　Biomechanics.