In this paper, novel fractal-shaped microstrip bandpass filters with one isosceles triangular defected cell and double defected cells using isosceles right-angled triangular resonator are presented, and their filter performances are calculated and optimized. Using etched fractal-shaped defections in patch, the proposed bandpass filters with a wide passband of about 1.48GHz, and dual passband centered at 9.61GHz and 12.013GHz are implemented, respectively, and all have transmission zeros. The novel filters have advantages such as simple and compact structures, small sizes, high selectivity and so on, and can be quite useful for future applications in wireless communication systems.