PROBLEM TO BE SOLVED: To provide a biological information processing system and a program capable of more accurately obtaining information related to arrhythmia based on pulse wave information than a method using an each beat interval value obtained from the pulse wave information.SOLUTION: A biological information processing system 100 includes: an acquisition section 110 capable of acquiring pulse wave information; a beat interval calculation section 130 for obtaining beat interval information for each given unit section based on the pulse wave information; and a determination section 150 for obtaining information related to arrhythmia. The determination section obtains a variation index of a beat interval and a deviation index from a given distribution based on N pieces of beat interval information obtained for each given unit section in a given statistical section including given unit sections of N times (N is an integer of 2 or more), and obtains the information related to the arrhythmia based on the variation index and the deviation index.SELECTED DRAWING: Figure 1【課題】脈波情報から求められる拍毎間隔値を用いる方法よりも正確に、脈波情報に基づいて不整脈に関する情報を求めることができる生体情報処理システム及びプログラムを提供する。【解決手段】生体情報処理システム100は、脈波情報を取得可能な取得部110と、脈波情報に基づいて、所与の単位区間毎の拍間隔情報を求める拍間隔算出部130と、不整脈に関する情報を求める判定部150と、を含む。判定部は、N(Nは2以上の整数)回分の所与の単位区間を含む所与の統計区間において、所与の単位区間毎に求められたN個の拍間隔情報に基づいて、拍間隔の変動指標及び所与の分布からの乖離指標を求め、変動指標及び乖離指標に基づいて、不整脈に関する情報を求める。【選択図】図1