The present application provides methods and devices for determining input information, and generally relates to the field of wearable devices. A method disclosed herein comprises: in response to a first part of a body of a user executing an action, acquiring target blood-flow information about the first part or a second part that corresponds to the first part; and determining input information according to the target blood-flow information and reference information. According to the methods and devices, the body of the user is used as an input interface, thus cause an interaction area to be increased, which helps to improve input efficiency and user experience.