A magnetic resonance imaging apparatus comprising: a cylinder shaped static magnetic field magnet; a cylinder shaped shim coil; a gradient coil; an RF coil; a transmitter; a receiver; a sequence controller; a computer; an imaging data acquiring unit configured, to acquire a plurality of 3-dimensional imaging data sets from an imaging region of a patient including a coronary artery providing a myocardium of the patient with blood, by applying a spatially selective RF labeling pulse to a labeling region including a part of an ascending aorta of a heart of the patient, in synchronization with a heartbeat of the patient without administration of a contrast medium; and a blood flow image generating unit configured to generate a plurality of blood flow image data sets of the heart based on the acquired plurality of 3-dimensional imaging data sets; wherein the imaging data acquiring unit is further configured to acquire the plurality of 3-dimensional imaging data sets while changing, for each of the plurality of 3-dimensional imaging data sets, respective traveling times of inflowing blood between each application of the spatially selective RF labeling pulse and each data acquisition, in a manner such that a start time of each data acquisition is in the same cardiac time phase regardless of using the different traveling times, by changing a delay time from a synchronization signal to the spatially selective RF labeling pulse, wherein the image data acquiring unit is configured to apply a spatially non-selective IR pulse at a delay time td1 from the time of an R wave of the synchronization signal, apply the spatially selective RF labeling pulse in the form of a spatially selective IR pulse to a slab covering said labeling region at a time interval ΔT after the application of the spatially non-selective IR pulse, start an image data acquisition at a travelling time BBTI after the application of the spatially selective IR pulse, wherein the time interval between the start of the image data acquisition and an R wave of the synchronization signal preceding the start of the image data acquisition is equal to a delay time td2, and the delay time td1, the delay time td2, the time interval ΔT and the traveling time BBTI are determined so that a start time of each data acquisition is in the same cardiac time phase regardless of using the different traveling times and so that the image data acquisition starts at a time when the longitudinal magnetization component Mz of the unlabeled myocardium becomes zero. a cylinder shaped static magnetic field magnet; a cylinder shaped shim coil; a gradient coil; an RF coil; a transmitter; a receiver; a sequence controller; a computer; an imaging data acquiring unit configured, to acquire a plurality of 3-dimensional imaging data sets from an imaging region of a patient including a coronary artery providing a myocardium of the patient with blood, by applying a spatially selective RF labeling pulse to a labeling region including a part of an ascending aorta of a heart of the patient, in synchronization with a heartbeat of the patient without administration of a contrast medium; and a blood flow image generating unit configured to generate a plurality of blood flow image data sets of the heart based on the acquired plurality of 3-dimensional imaging data sets; wherein the imaging data acquiring unit is further configured to acquire the plurality of 3-dimensional imaging data sets while changing, for each of the plurality of 3-dimensional imaging data sets, respective traveling times of inflowing blood between each application of the spatially selective RF labeling pulse and each data acquisition, in a manner such that a start time of each data acquisition is in the same cardiac time phase regardless of using the different traveling times, by changing a delay time from a synchronization signal to the spatially selective RF labeling pulse, wherein the image data acquiring unit is configured to apply a spatially non-selective IR pulse at a delay time td1 from the time of an R wave of the synchronization signal, apply the spatially selective RF labeling pulse in the form of a spatially selective IR pulse to a slab covering said labeling region at a time interval ΔT after the application of the spatially non-selective IR pulse, start an image data acquisition at a travelling time BBTI after the application of the spatially selective IR pulse, wherein the time interval between the start of the image data acquisition and an R wave of the synchronization signal preceding the start of the image data acquisition is equal to a delay time td2, and the delay time td1, the delay time td2, the time interval ΔT and the traveling time BBTI are determined so that a start time of each data acquisition is in the same cardiac time phase regardless of using the different traveling times and so that the image data acquisition starts at a time when the longitudinal magnetization component Mz of the unlabeled myocardium becomes zero.