Cu-based quaternary SMA’s are less expensive, easy to prepare and exhibits excellent shape memory effect. In this paper, Cu-Al-Be-Mn quaternary alloys taken in the range of 11-14 wt% of Al, 0.2-0.4 wt % of Mn, 0.47 wt% of Be and rest is copper were synthesized through ingot melting method in the inert atmosphere and also conducted bend test to demonstrate the shape memory property after step quenching process at room temperature. Beryllium kept constant and manganese concentration in the alloy was varied to evaluate the fracture toughness of each alloy specimens by taking stress intensity factor (KIC) into account. In the current study modified single edge cracked plate tension specimen was prepared by using wire EDM. Fracture toughness of shape memory alloys is determined by testing the alloy specimens on uniaxial tensile testing machine, which are initially tested under low fatigue tensile loading to create a pre crack and then subjected to a uniaxial tensile loading until fracture. After fracture maximum load was noted down and stress intensity factor (KIC) can be evaluated for all the alloy samples. The fractured surface of the specimens was studied under scanning electron microscope (SEM) and examined the effect of composition and notch configuration on the fracture behaviour of SMA. An experimental result shows that the alloys exhibits good fracture toughness with KIC values up to 41 MPa m ^ 0.5 and stress intensity factor (KIC) increases with the increase in wt % of manganese