An elliptical exercise machine comprising: a base; two swing rods connected pivotally to said base and spaced apart from each other in a left-to-right direction; a flywheel disposed rotatably on said base; two supporting rods connected respectively and pivotally to bottom ends of said swing rods and connected to said flywheel; two pedal rods disposed respectively, pivotally, and movably on said supporting rods; characterised by a motion transmitting device including a fixed member disposed fixedly on said base, a rotatable member disposed rotatably on said fixed member and locked releaseably on said fixed member at a selected one of a plurality of angular positions, two cranks having upper ends connected respectively and pivotally to left and right sides of said rotatable member, and lower ends opposite to said upper ends, and two links each having a first pivot portion connected pivotally to a respective one of said pedal rods, a second pivot portion disposed above said first pivot portion and connected pivotally to a respective one of said swing rods, and a third pivot portion spaced apart from said second pivot portion and connected pivotally to said lower end of a respective one of said cranks, said links being driven by said cranks to move said pedal rods forwardly and rearwardly on said supporting rods, respectively. a base; two swing rods connected pivotally to said base and spaced apart from each other in a left-to-right direction; a flywheel disposed rotatably on said base; two supporting rods connected respectively and pivotally to bottom ends of said swing rods and connected to said flywheel; two pedal rods disposed respectively, pivotally, and movably on said supporting rods; characterised by a motion transmitting device including a fixed member disposed fixedly on said base, a rotatable member disposed rotatably on said fixed member and locked releaseably on said fixed member at a selected one of a plurality of angular positions, two cranks having upper ends connected respectively and pivotally to left and right sides of said rotatable member, and lower ends opposite to said upper ends, and two links each having a first pivot portion connected pivotally to a respective one of said pedal rods, a second pivot portion disposed above said first pivot portion and connected pivotally to a respective one of said swing rods, and a third pivot portion spaced apart from said second pivot portion and connected pivotally to said lower end of a respective one of said cranks, said links being driven by said cranks to move said pedal rods forwardly and rearwardly on said supporting rods, respectively. a fixed member disposed fixedly on said base, a rotatable member disposed rotatably on said fixed member and locked releaseably on said fixed member at a selected one of a plurality of angular positions, two cranks having upper ends connected respectively and pivotally to left and right sides of said rotatable member, and lower ends opposite to said upper ends, and two links each having a first pivot portion connected pivotally to a respective one of said pedal rods, a second pivot portion disposed above said first pivot portion and connected pivotally to a respective one of said swing rods, and a third pivot portion spaced apart from said second pivot portion and connected pivotally to said lower end of a respective one of said cranks, said links being driven by said cranks to move said pedal rods forwardly and rearwardly on said supporting rods, respectively.