We propose a core-shell microfiber-shaped cardiac tissue as a drug screening model with a fixation-free contractile force measurement system. The contractile force of the hiPSC-derived cardiac tissue can be calculated only with a motion analysis, thanks to a shell of hydrogel covering the cardiac tissue. Thus, the system can evaluate the behavior of the tissue in drug screenings without any specific equipment. We demonstrated drug screening tests with pharmaceuticals on our microfiber tissues, resulting in 102.7% increase of contractile force with isoproterenol and 56.3% decrease with propranolol. Our cardiac drug screening model can easily reproduce and evaluate cardiac disease models, and would contribute to the pathological research of unexplained cardiac diseases and pharmacokinetic testing.