This paper provides an experimental result of non-contact vital sensing by a Doppler sensor for multiple targets. This is based on the signal processing scheme that is termed as differential of accumulation for real-time serial-to-parallel converter (DARS). To the best of authors' knowledge, there is no extant studies dealing with multiple targets with a Doppler sensor. In this experiment, we employ a simulated body, not a human body, for a precise evaluation of the accuracy of the measurement. Additionally, the experiment confirms that the DARS can sensitively detect the sudden change of the vibration of the simulated body. This is suitable for the sudden illness detection.