The optimum cultural conditions for production of yellow pigment by Monascus purpureus MMK2 were investigated in liquid culture. Monascus purpureus MMK2 was shown to give the maximum production of yellow pigment in the medium containing of 3.0% wheat flour, 0.15% $NaNO_3$, 0.25% $Na_2HPO_4;12H_2O;and;0.15%;MgSO_4;7H_2O$. The optimal culture conditions for temperature and initial pH were $30^{circ}C$ and 6.5, respectively. The yellow pigment production reached a maximum level at the 7th day of cultivation.