Abstract: The traditional elliptic function lowpass filter is based on highimpedance and lowimpedance lines, which are equivalent to semilumped inductors and capacitors respectively. However, this type of filter is of large size. Especially at low cutoff frequency, it is difficult to integrate with bandpass filter on the sizelimited superconducting wafer. Therefore, this paper presents a novel design of HTS lowpass filter based on folded interdigital resonators. The design has the advantages of steep band edge, high outofband rejection, and compact size. EM simulation results demonstrate the validity of the design. This design is very suitable for compact lowpass filter at low frequency band.