Oriented covalent immobilized (2)-adrenergic receptor ((2)-AR) CE (OIRCE) was developed to determine the interactions between a set of natural extracts of Radix Paeoniae Rubra (NERPR) and (2)-AR, and to predict the activity of NERPR. The inner capillary surface is chemically bonded with stable (2)-AR coating via microwave-assisted technical synthesis. The modified capillaries were characterized via infrared spectroscopy and fluorescence microscopy. Furthermore, the bonding amounts of (2)-AR were first obtained via fluorescence spectroscopy method. In determining the amount of bonded (2)-AR, the regression equation A = 576707C+35.449 and the correlation coefficient 0.9995 were obtained. This result revealed an excellent linear relationship in the range of 2x10(-4)mg/mL to 1x10(-3)mg/mL. The normalized capacity factor (K-RCE) was obtained using OIRCE in evaluating drug-receptor interactions. Related theories and equations were used to calculate K-RCE values from apparent migration times of a solute and EOF. The order of K-RCE and the binding constant (K-b) values between drugs and (2)-AR was well consistent. The results confirmed that the OIRCE and K-RCE values can be effectually used to investigate drug-receptor interactions, and OIRCE has the potential to predict drug activity and to select leading compounds from natural chemicals.