The purpose of this paper is to do the heart rate variability index (HRV) evaluation of human based on GM (h, N) in grey system theory, so as to construct an alarm sign for our health. This paper can be divided into four parts. First, the characteristics of heart rate variability index examination in human are presented, such as, pressure index (PSI), total power (TD), very low frequency (VLF), high frequency (HF), the standard deviation of the N-N interval (SDNN). Second, we present GM (h, N) as our mathematics model. Third, based on the mathematics model, which we mentioned, to get the evaluation. Finally, we can provide the analyzed results become an alarm sign for human health.