Provided are a mobile terminal (13), an accessory device (14), and a blood pressure measuring system. The mobile terminal (13) comprises a terminal body and at least a first heart rate sensor (11) the mobile terminal (13) is used together with the accessory device (14) comprising at least one second heart rate sensor (12). The first heart rate sensor (11) and the second heart rate sensor (12) collect simultaneously at least two heart rate signals. The first heart rate sensor (11) and the second heart rate sensor (12) are electrically coupled with a processor (131). The processor is provided in the mobile terminal (13) or the accessory device (14). The processor (131) calculates a time difference for a heart rate signal to be transmitted from an aorta to two body locations, and calculates the blood pressure of a user based on the time difference of transmission and a predetermined blood pressure calculating parameter. In the mobile terminal (13), accessory device (14) and blood pressure measuring system, heart rate sensors (11, 12) are installed on an existing mobile terminal and terminal accessory so as to measure the blood pressure of a user, thereby measuring the blood pressure of the user at any time and at any place without the need of a specialized blood pressure measuring device.Linvention concerne un terminal mobile (13), un dispositif auxiliaire (14) et un système de mesure de la pression artérielle. Le terminal mobile (13) comprend un corps de terminal et au moins un premier capteur de fréquence cardiaque (11) le terminal mobile (13) est utilisé conjointement avec le dispositif auxiliaire (14) comprenant au moins un second capteur de fréquence cardiaque (12). Le premier capteur de fréquence cardiaque (11) et le second capteur de fréquence cardiaque (12) collectent simultanément au moins deux signaux de fréquence cardiaque. Le premier capteur de fréquence cardiaque (11) et le second capteur de fréquence cardiaque (12) sont raccordés électriquement à un proc
