4-(4-Aminophenyl)-5-ethoxycarbonyl-6-methyl-3,4-dihydropyrimidin-2(1H)-one (AEMD) was synthesized and the crystal structure of AEMD was determined by single crystal X-ray diffraction. This molecule crystallizes in a monoclinic P2(1)/c space group with a=11.237(4)nm, b=5.799(2)nm, c=22.394(7)nm, α=90o, β=91.048(5)o, γ= 90o, Z=4. The interactions between AEMD and bovine serum albumin (BSA) were investigated using fluorescence spectroscopy, the results revealed that AEMD quenched the BSA fluorescence; the corresponding thermodynamic parameters(ΔH?0 and ΔS?0) shown that the action forces were mainly hydrogen bond and van der Waals interaction; the binding distance was estimated to be about 2.19 nm according to F?rster’s non-radioactive energy transfer theory; the synchronous fluorescence showed that the AEMD induced conformational changes of BSA