In this study, stress intensity factors at crack tip in a simply-supported elastic beam with multiple cracks subjected to moving loads is considered. Massless rotational spring is used for modelling the crack. Natural frequencies and corresponding mode shapes are obtained by the transfer matrix method. Equation of motion for the forced vibration problem is then solved numerically by the Newmark method. Considering four different damage cases, variation of the maximum deflections of the beam with crack size and location for various load speeds is investigated. Stress intensity factors at crack tips are studied in detail for load speeds, crack size and location.