The growth and red pigment production of Monascusruber on rice starch agar were studied by following the time courses of 1) length and tip number of aerial and substrate hyphae generated from single spores and 2) radius and pigment absorbance of colony. Logarithmic increases with time in hyphal length and tip numbers were observed during the first 0.92 d for substrate hyphae and 1 d for aerial hyphae. The specific growth rates estimated from the hyphal growth were 6.2 d(-1) for substrate hyphae and 5.5 d(-1) for aerial hyphae. These results closely agreed with that of 6.1 d(-1) obtained from the extension of colonial radiuses. Doubling time suggested from this specific growth rate is 0.114 d. The pigment formation was found to delay for 35 doublings in hyphal length extension since spore inoculation. Careful inspection showed that red pigment was locally formed by upper part of substrate mycelium.