This paper summarizes the synthesis, growth and the effect of the position of the substituent in the thienyl ring and also the properties of the grown chalcone crystals, 2-CTP and 3-CTP. The formation of compound is confirmed by the re- corded H¹NMR spectra. A FT-IR spectrum confirms the presence of all functional groups in both of the crystals. Single crystal XRD reports that even though these two compounds crystallize in monoclinic crystal system, 2-CTP has centro- symmetric P2₁/c space group and 3-CTP has non-centrosymmetric space group P2₁. Thermal properties of grown crys- tals analyzed by TG/DTA study explain that the 3-CTP compound is slightly more stable than 2-CTP. The transparency of these isomers in the vis-IR region has been studied. Second and third order nonlinear optical properties of 3-CTP and 2-CTP crystals have been investigated by powder SHG and Z-scan technique respectively.