Danggui, Agelicae Sinensis Radix, is a widely used Chinese herb to enrich blood, but its quality cannot be effectively assessed by the known chemical markers such as ferulic acid, ligustilide, polysaccharides, etc. A new bioassay was therefore developed to quantify the Enrich-Blood Bioactivity (EBB) for the quality assessment of Danggui raw materials. Danggui sample was first extracted with ethanol and water, respectively. Then the ethanolic extract and water extract were mixed as a test sample to quantify the amount of EBB by mice experiment. The blood deficiency mode in mice was developed by intraperitoneal injecting cyclophospharmide and phenylhdrazine hydrochloride. The quantity of red blood cell was chosen as EBB marker. Cyclosporine A was chosen as a control substance. EBB in analytes was quantified by the amount reaction of parallel line analysis (3, 3') method. The results indicated that the reliability test for quantifying EBB was passed through and the measured value was valid. The analytes showed the significant EBB (P < 0.05). The correlation coefficient was 0.9984 (n=5) between the amount of cyclosporine A (0.035-0.56 g x kg(-1)) and the increased number of red blood cell. The relative standard deviation (RSY) on the amount of EBB was estimated to be 6.15% (n = 6) by six replicated tests, and the confidence limit rate was 26.68% (n = 6). Five Danggui samples, which were collected from different cultivation areas with various morphological characters, showed the variety of EBB in the range of 21.95-44.16 U x g(-1). It is concluded that the developed method is accurate to quantify the EBB of Danggui raw materials, and is therefore suitable to assess its quality.