The fruit of Evodia officinalis (Rutaceae) is known for containing a number of indoloquinazoline and quinoline type alkaloids. Evodiamine, evocarpine and rutaecarpine are the major constituents of Evodiae Fructus. These alkaloids were isolated and determined by forming complex compounds from Evodiea Fructus. For the determination of these alkaloids, a new spectrophotometric method was developed with a simple and selective sample clean-up using thiocyanatocobaltate [II] complex ion. The absorbance of alkaloidal complex in 1.2-dichloroethane solution was measured at 625 nm. A calibration curve for the alkaloids isolated from Evodia Fruit was linear over the concentration range of $1.0{sim}6.0;mg/ml$. The method proved to be rapid, simple and reliable for the isolation and the determination of the alkaloids in Evodiae Fructus.