To analyse the reference value of photoplethysmogram on different position of normal adults.the photoplethysmogram of the cheeks,linguales,nail matrixes of ring fingers and cunkou(radial artery)of normal adults with “BC-4”photoplethysmograph were examined and analysed.The results showed that the indexes of time reflecting cardiac pulsation(Tag,Tab,Tac,Teg)and the specific value reflecting cardiac function(Tab/Tag,[Tae-Tab]/Tag,Tae/Tag)on different position were consistent.The indexes of height(He),angle(ANbag,Anabc),area(Aae,Aeg,Aag)and speci...