The objective of the proposed research is to improve communication and sensing performance by utilizing reconfigurable intelligent surfaces (RISs) at millimeter-wave (mmWave) band. The functionality of integrated sensing and communication at mmWave band has become an important feature for the next generation of wireless systems. To solve the problems of severe path loss and sensitivity to blockages in mmWave networks, RISs which are passive reflective arrays have been proposed with the advantage of flexible configuration of radio propagation environments for signal enhancement and coverage expansion. The proposed research will investigate RIS-aided communication and sensing in the following aspects: (1) theoretical analysis of coverage performance for single-RIS and multi-RIS links; (2) multi-RIS deployment strategy for indoor scenarios from communication perspective; (3) evaluation of optimal platform structure for integrated sensing and communication system; (4) design of 3D imaging algorithm in RIS-aided sensing systems.