Triglycine sulphate crystal is a well known ferroelectric crystal which has ferroelectric domains at room temperature. The drawback of pure TGS crystal is its tendency to polarization reversal. To overcome this difficulty and to improve the ferroelectric properties of the TGS crystals, it has been doped with amino acids, metal ions etc. In the present work, growth, structural, mechanical, FTIR and optical characterization of TGS crystal admixtured with Perchloric acid. Ferroelectric crystals of pure and Perchloric acid-admixtured Tri Glycine Sulphate (TGS) single crystals were grown by slow evaporation technique. The cell parameters of the grown crystals are evaluated from single crystal XRD and the results are compared. UV-VIS spectra studies explain the transmission ability of the grown crystals in the visible range. FTIR studies are performed to identify the presence of various functional groups present in the grown crystals. The nonlinear optical (NLO) property of the grown crystal was confirmed by Kurtz-Perry powder technique and a study of its second harmonic generation efficiency in comparison with potassium dihydrogen phosphate KDP has been made. The mechanical strength of the crystal was estimated by Vickers hardness test.