The substituted chalcones (C1-5) was prepared by reaction of acetophenone (a) and aromatic aldehydes (b1-5). One series of N-phenyl pyrazoline analogues (K1-K5) were synthesized by reaction of the substituted chalcones (C1-5) with phenyl hydrazine in acidic medium. Another series of 3, 4-dihydropyrimidine-2-one analogues (K6-K10) were synthesized by reaction of substituted chalcones (C1-5) with ethanolic urea in alkali medium. The yield of the synthesized analogues ranged from 62-76%. The structures of the synthesized analogues were verified by FTIR,1H-NMR, mass spectral data and physical analysis. The structures of the synthesized heterocyclics are correlated with the spectral analysis and the synthesized heterocyclics structures are well agreed with the proposed structure.