In the course of our studies on the chemical constituents of the aerial parts of Skimmia laureola, a number of coumarins isogospherol (1) heraclenol (2), (+)-7-methoxy-6-(2`R-methoxy-3`-hydroxy-3`-methyl butyl) coumarin (3), 5, 8-dimethoxy coumarin-2H-1benzopyran-2-one (4), 7-methoxy-6-[2`-oxo-3`-methyl butyl] coumarin (5), (+)-ulopterol (6), were isolated. In addition various quinoline alkaloids, 4-methoxy-l-methyl-3-(2`S -acetoxy -3`-ene butyl) -2-quinolone (7), 4-methoxy-l-methyl-3-(2`S-acetoxy-3`-hydroxy butyl)-2-quinolone (8), 3-hydroxy-2, 2, 6-trimethyl -3, 4, 5, 6- tetrahydro-2H-pyrano [3, 2- c] quinoline-5-one (9), 4-methoxy-l-methyl-3-(2`-oxo-3`-methyl butyl)-2-quinolone (10), 4-methoxy-l-methyl-3-(2`S-hydroxy-3`-ene butyl) -2-quinolone (11), methyl isoplatydesmine (12) ribalinin (13) and dictamnine (14) were also isolated from Skimmia laureola. The structures were established by spectroscopic studies. In this paper we report the X-ray diffraction studies on inhibitor of platelet aggregation dictamnine (14).