Abstract: A new simple and rapid micro color reaction of morphine and its derivatives is reported in this paper. It is sensitive and specific. 45 compounds, including alkaloids, nitrogen-containing drugs and phenols were tested by this reaction, but none of them gave violet-blue color as that of morphine (Tab. 1). Procedure: Dissolve a small amount of morphine in 1-2 drops of conc. H₂SO₄, in a small test tube (0.7×7cm), add 1 drop of nitrobenzene, then heat with a small flame just to boiling. After cooling, dilute with 3-4 drops of water and shake with 1-2 drops of n-butanol, a violet-blue color occurs in n-butanol layer and it shows maximum absorption at 552 mu. (Fig.Ⅰ). The limit of identification of this reaction is 2γ for morphine-HCl. Detection of morphine in urine using the proposed reaction: Boil the 100 ml urine with 5 ml conc. HCl in order to hydrolyse the conjugated mophine, make the solution alkaline with NaHCO₃, and extract with 80 ml n-butanol--benzene (1:1) or isoamyl alcohol--n-butanol (1:1). Separate the organic solvent layer and extract with 10 ml 5% H₂SO₄, make the acid extract alkaline with NaHCO₃ and extracted with 30 ml isoamyl alcohol--ethyl acetate (1:1)or n-butanol--ethyl acetate (1:1). After evaporating the organic solvent to dryness, dissolve the residue in 4-6 drops of conc. H₂SO₄ and test as mentioned above, except 12-16 drops of water and 4 drops of n-butanol are used instead of 3-4 drops of water and 1-2 drops of n-butanol. 100γ of morphine-HCl in 100 ml. urine can be detected distinctly.