The research includes preparation ligand (DMAB) and itsComplexes with Cu (II) as symbol (M1), Fe (III) as symbol (M2) and Cr (III) as symbol (M3). The identity of prepared compounds has been characterized by spectral methods, infrared ray (IR) and measures melting point (m.p.). Also the research included study of the Mechanical properties by ultrasonic waves velocity technique at 40 KHz frequency, absorption coefficient of ultrasonic waves, relaxation time, relaxation amplitude, specific acoustic impedance compressibility, and bulk modules has been measured and all the results showed that all properties decrease with increase ultrasonic waves velocity except the specific acoustic impedance and bulk modules which was increase with increase velocity and all the results compared with similar compound.