Particle detectors at future lepton or hadron colliders will require covering a very large area with a tracker with fine spatial resolution of O(10)um. A timing capability of O(10)ps in addition should improve the tracking reconstruction, particle identification of charged particles and mass measurement of newly discovered particle. Capacitive-coupled Low-Gain Avalanche Diode (AC-LGAD) is a semiconductor tracking detector with precise timing resolution and spatial resolution developed by KEK and Tsukuba group collaborating with Hamamatsu Photonics K.K. (HPK). A 100um x 100um pitch pixel type sensor and 80um pitch with 10mm length strip type sensor with 50um active thickness have been successfully developped with fully uniform gain across sensor active area. In this presentation we will present about recent status of the development of AC-LGAD detector and possibility of improvement for timing resolution and radiation tolerance.