Abstract: Extraction conditions, basic properties and the stability of the yellow pigment produced by a new marine actinomycete strain MA01, which was isolated from Weihai sea area, were investigated in this paper.The maximum absorption wavelength was measured, and the stability of the pigment was assessed under the conditions as following:the different pH values, UV, fluoresnt lighting, the different temperatures, some kinds of ions, oxidant/reducer and preservatives. In addition, the 16S rDNA fragment of MA01 was amplified by PCR for molecular characterization, and the phylogenetic tree was constructed. Results showed that the maximum absorption wavelength of this yellow pigment was 300nm. The pigment was extracted better by ultrasonic extraction method than by solvent method. This yellow pigment was classified as a kind of water-soluble pigment, and is soluble in methanol and ethanol. Furthermore, it was stable at the temperature below 60℃ and under the neutral and alkaline conditions, but sensitive to oxidant, while had a good resistance to UV and light.Some metal ions (e.g. K+, Na+, Mg2+, Mn2+, Ca2+) and common preservatives (e.g. salt and sucrose) did not affect the stability of the pigment. Phylogenetic tree analysis of 16S rDNA sequence indicated that the similarity between MA01 and multiple strains of Streptomyces sp.was higher than 99%. Therefore, MA01 was identified as a new strain belonging to Streptomyces sp., and had good value for research.