Abstract: A pen-sized keyboard arrangement of the present invention comprises a flexible keyboard member, a rolling mechanism and an electrical connection unit. The rolling mechanism includes a base and an elongated rolling pole pivotally connected to the base. The rolling mechanism defines a longitudinally extending an elongated groove. One end of the rolling mechanism is pivotally connected to the base. The other end thereof is used for being rotated by a user for rolling in and pull out the flexible keyboard member. The flexible keyboard member includes a buffer for absorbing the deformation of the flexible keyboard member when the flexible keyboard member is rolled in or pulled out. The rotating mechanism can rotate the electrical connection unit about a desired angle for being properly viewed by a user. Such a keyboard arrangement is apparently easy for being carried and provides a large area for each key-press thereby facilitating a rotating operation by a user.