In the previous report, we showed that the properties of harusame noodles are markedly affected by the kind of starch used and the method of preparation.In this study, an experiment was conducted on harusame noodles prepared using mung bean starch in combination with potato starch and sweet potato starch for the purpose of discussing the properties of noodles prepared by an extrusion method. The changes in the degree of gelatinization, the texture and the organoleptic characteristics, as judged on sensory evaluation of harusame noodles, were studied in comparison with in the case of commercial harusame noodles.The degrees of gelatinization of mung bean starch noodles during the process of harusame noodle manufacture and preservation were determined. The degree of gelatinization was 56% immediately after extrusion at 80°C, 83% after heating in boiling water for 3 minutes and 74% after finishing by direct drying, whereas the degree of gelatinization was markedly lower after freezing and after storage for 6 months at room temperature, which was 45% and 39%, respectively.The degree of gelatinization of mung bean starch noodles at each stage was 5 to 16% lower than that of noodles made of a potato and sweet potato starch mixture (1:1), and so it was found that the gelatinization of mung bean starch noodles was difficult and that they easily underwent retrogradation as compared with the mixed starch (1:1) noodles.Microscopic observation showed that mung bean starch noodles were not sufficiently gelatinized with the extrusion system; they had a non-uniform texture and contained ungelatinized starch granules. Three kinds of commercially made harusame noodles showed marked differences in texture, these were caused by the kinds of starches or the method of preparation. Fibrous orientation was observed on the surface of commercially made Chinese “Lungkow” harusame noodles and this fibrous texture being considered to contribute to their transparency, luster and physico-chemical properties. The degree of gelatinization was 36% for Chinese “Lungkow” harusame noodles, and 34% and 42% for commercial Japanese harusame noodles made with the suspension system and the extrusion system, respectively.The organoleptic characteristics of harusame noodles were found to be markedly affected by the properties of the starches used and the method of preparation, and the results obtained resembled those of the measurement of physicochemical properties.