Development of a Superconducting Cavity Injector Cryomodule for the compact ERL (cERL) is being continued at KEK since 2006. Design of a cryomodule containing three 2-cell 1.3-GHz cavities is almost completed and will be ordered soon. Status of R&D and design details are reported. SC CAVITY SYSTEM FOR COMPACT ERL INJECTOR AT KEK An injector for cERL is required to accelerate a CW electron beam of 100mA to 10MeV [1]. In this application, critical hardware components are not cavities but RF input couplers and HOM dampers. Several combinations of number of cavity and cells per cavity were examined, and a three 2-cell cavity system was chosen for cERL. Each cavity is drove by two input couplers to reduce required power handling capacity and also to compensate coupler kick. HOM coupler scheme was chosen for HOM damping, and 4 or 5 HOM couplers are put on beam pipes of each cavity. Because of simplicity cavities are cooled by jacket scheme. Figure 1 is the drawings of the cyomodule system for the injector part. Basic parameters of the cavity are summarized in Table 1. Table 1: Basic Cavity Parameters Frequency 1.3 GHz Number of cell 2 R / Q 205 Ω Operating Gradient 14.5 MV / m Number of Input Coupler 2 Coupler Power 167 kW Coupler Coupling Q 3.3 x 10 Number of HOM coupler 4 or 5 Operating Temperature 2 k