Abstract: Modern public decision is becoming increasingly dependent on the support of scientific expertise. A well-functioning sci-tech consulting system is an important measure for guaranteeing the implementation of decision-making in a scientific way. At the same time, it is also a significant symbol of modern national governance systems and that which reflects the modernization level of governance abilities. This paper outlines a Japanese sci-tech consultation system and summarizes its characteristics, the brief rundown of which is presented as follows. On the one hand, this decision-making system has been embedded with a set of consultation system that is presided by Council for Science, Technology and Innovation (CSTI), takes various Councils as the main subjects, and adopts a top-down consultation opinion provision approach in support of the decision-making. On the other hand, outside the decision-making system, there are academic and industrial consulting systems led by Japanese academic committees, which adopts a bottom-up approach in offering advice, suggestions, and decision-making references. These two consulting systems complement and embrace each other, which finally contributes to the symbiosis and integration of Japanese sci-tech decision-making and consultation. This paper conducts an in-depth analysis of the features and causes of Japan’s sci-tech consulting system from three aspects: (1) the institutionalization and systematization. Most of the consulting organs in the decision-making system are institutionalized, whose establishment, membership, functions, etc. take the clear stipulations in laws or government decrees as the principles; the related administrative organs responsible for scientific decision-making, ranging from the cabinet, provincial governments to local governments, are equipped with corresponding consulting organs to provide decision-making support; under the overall leadership of CSTI, various types of consulting organs at all levels have formed a division of labor and cooperation with their own focuses; (2) the integration and embeddability. The consulting process of sci-tech decision-making is deeply embedded in the decision-making process, and decision-making and consulting have the features of integration and symbiosis. Consulting organs, represented by councils, are one type of administrative organ. The Japanese administrative system itself has been embedded with consulting organs and consulting functions, and has become an important place where multiple forces and subjects like experts, stakeholders, industry, the public, and administrative officials interact to promote policy compilation;(3) the “two wheels” of the sci-tech consulting system led by CSTI and Science Council of Japan. The “two wheels” are distinctive in function positioning and cooperative in division of labor. As the highest consulting organ in the sci-tech field, CSTI leads and promotes policy compilation in a “top-down” approach. The Science Council of Japan, as the highest academic institution representative of the scientific community, adopts a “bottom-up” model to extensively collect and assimilate opinions and suggestions from the scientific community. The “two wheels” cooperate and coordinate intimately to promote the inclusive development of different consulting entities inside and outside the system.This paper compiled the general sci-tech plan used in Japan into a research case, from which the contributions of sci-tech consultations toward major sci-tech decisions in Japan, and relevant experience China can learn from, were analyzed and summarized.