Abstract: 1. The condensation of 34 amino-containing and heterocyclic nitrogen con- taining drugs with fluorescein chloride to form Rhodamine dyes by means of spot test method was investigated. 2. The method was found to be 2-5 times more sensitive than that of Feigl's test tube method. 3. A series of observations on spot test shows that the condensation between the primary aromatic amines with fluorescein chloride is apt to take place (sensibility 2-4γ). It may be applied as a preliminary test for the detection of amino- containing or heterocyclic nitrogen containing drugs.