In recent years, the use of augmented reality (AR) systems has become quite common. Many marker-based AR systems can input the positions of physical markers and realize a combination of real-world and computer-generated graphics. However, few systems can recognize other information such as fingertip motions. The objective of our study is to create AR environments in which users can manipulate virtual objects by using natural finger motions. Toward this end, we propose a novel marker-based AR system called "ARForcc." ARForcc enables users to measure the 3D position of markers as well as also the distribution of force vectors that arc applied by a user. Using this system, users can manipulate virtual objects using various finger motions.Our proposed system comprises a camera and an input device. The input device is an clastic body and it comprises two types of markers. One is a square-shaped marker that enables a user to detect the position of the device. The other markers arc small circular-shaped ones that arc placed within the clastic body. The positions of the circular markers arc moved when a user applies a force to the device. This enables force detection.