Background: Recently, there has been a global trend toward the use of natural substances present in fruits, vegetable, oilseeds and herbs as medicine and functional food.. Taken together, administration of Angelica sinensis extract may have beneficial effects in the treatment of hereditary sphryocytosis by measuring the osmotic fragility effects. Objective: To Validation of Osmotic Fragility Test using a modified new Garden Angelica Reagent Methodology: The human red blood cells were collected in heparin Anticoagulant and Osmotic fragility test reagent was prepared according to Daci and Lewis techniques.100 gram of dried root parts of Angelica were purchased from Sakaka herbal medicine farmer's cooperative, Aljouf. The botanical identification was made by herbalist, Aljouf University, Saudia Arabia. The roots were ground with a Wiley mill to pass a 1 mm screen and were extracted with Distilled water at 40°C for 12 h. The extract was then filtered through Advantec No. 1 filter paper. The collected filtrate suspension concentration was 40 g/dl then was diluted in different concentrations using normal saline. After evaporation, the concentrated extract was stored in a refrigerator at 2°C until used. Osmotic fragility test was done for heparinized whole blood samples of 30 healthy males using both the osmotic fragility(phosphate buffer saline) and the new modified angelica reagents(AR).The range of values represented the percentage of erythrocyte lysis at each corresponding phosphate buffer saline concentration (PBS) and angelica reagents(AR) were calculated. The corresponding concentration of PBS solution that caused 50% lysis of erythrocytes defined the MCF index (Dewey et al., 1982; Krogmeier et al., 1993). The erythrocyte osmotic fragility curve; the plot of percentage of erythrocyte lysis versus concentrations of PBS solution was used to obtain the MCF values. The relative capacity of the chemical stabilize or destabilize erythrocyte membrane was evaluated as percentage of the quotient of the difference between MCF values of test and control samples to the control sample (Parpart et al., 1947; Chikezie, 2007). Results: The mean (±SD) MCF values of the MCF for PBS was 4.38±2.04 and for AR was 3.71±0.98 of blood samples obtained from donors. In addition, the erythrocytes exhibited significantly (p<0.05) decreased MCF values when AR was used. This was an obvious reflection of higher fragility index of these erythrocytes. Conclusion: One of the properties of an ideal the new modified angelica reagent applicable for in vitro blood processing procedure for the osmotic fragility test is one that exhibit minimum or insignificant destabilizing effect on erythrocyte membrane. The present study showed the critical concentrations of angelica reagent that engendered membrane destabilization of human erythrocyte.