Spiral MRA is a new accelerated time-of-flight MR angiography (TOF MRA) with spiral data acquisition, which acquires MR data by traveling through k-space with spirals. Acquisition window (AW) is a new parameter, which indicates the degree of under-sampling related to image quality and acquisition time. In this study, suitable flip angle (FA) and AW for Spiral MRA was evaluated by a 5-point scale and signal profile analysis. In conclusion, the suitable FA was 25° to demonstrate each artery and suppress the background signals. AW should be set to 10 or less to avoid vessel blurring.