In the present paper, a boundary collocation method (BCM) is used for evaluation of stress intensity factor for single edge notch high strength beam under three point bending loading condition. Six simply supported beams of dimensions 400cm×50cm×80cm and clear span of 320cm with three each of notch depths 8cm and 16cm were used for the investigations. An appropriate complex stress function is presumed which satisfies the equilibrium equations for a single cracked beam for infinite domain, the function also satisfies the stress singularity condition at crack tip. The unknown coefficients of the adopted stress functions are determined solving over determined simultaneous equations, obtained by enforcing boundary conditions along the edges of the beam. Stress intensity factor and fracture toughness was then evaluated. The fracture toughness values were compared with the values obtained from a two parameter fracture model developed out of experimental results. Keywords: Stress intensity factors, BCM, HSC, Notched Beam, Complex stress functions.