Provided are a blood flow analysis device, method, and program that can capture a backflow location even when there is a backflow at an unexpected location, and can reduce the risk of oversight of the backflow location. A blood vessel region extraction unit (11) that extracts a blood vessel region from a blood vessel image obtained by photographing a subject including blood vessels, and a flow velocity vector acquisition unit (12) that acquires a flow velocity vector representing a blood flow velocity and a blood flow direction in the blood vessel region. The central axis extending in the direction of extension of the blood vessel region is set, the integral value obtained by integrating the direction component of the central axis of the flow velocity vector in the time axis direction is calculated, and the blood flow in the blood vessel region is calculated based on the change in the integral value. A backflow specifying unit (13) for specifying the presence or absence of backflow.想定外の箇所に逆流があった場合でも、その逆流箇所をとらえることができ、逆流箇所の見落としリスクを減らすことができる血流解析装置および方法並びにプログラムを提供する。 血管を含む被写体を撮影した血管画像から血管領域を抽出する血管領域抽出部（１１）と、血管領域内における血流速度および血流方向を表す流速ベクトルを取得する流速ベクトル取得部（１２）と、血管領域の延伸方向に延びる中心軸を設定し、流速ベクトルの中心軸の方向成分を時間軸方向に積分した積分値を算出し、積分値の変化に基づいて、血管領域内の血流の逆流の有無を特定する逆流特定部（１３）とを備える。
