In June 2020, China unilaterally announced two seasonal closures on squid fishing in certain areas of the high seas that apply to the Chinese distant water fishing fleets. Such closure refers to the withdrawal of the Chinese distant water fishing fleet from part of the high seas where they regularly operate. It is an innovative conservation measure initiated by a nation-state with the significance for global ocean governance and meeting the requirements from the UN Sustainable Development Goals. This paper is designed to seek the possibility, through a qualitative study and interpretive analysis, of whether such an innovative conservation measure can be introduced into the fishery management in the Southern Ocean, currently mainly under the framework of CCAMLR. This paper attempts to answer some questions with this new introduction. First, whether this kind of seasonal closure is applicable or feasible within the framework of CCAMLR. Second, whether this kind of seasonal closure would infringe upon or disrupt existing regimes, such as marine protected areas (MPAs) created by CCAMLR. Third, how and to what extent such a measure is supported by best scientific evidence so as to reach optimal effectiveness. In this regard, firm support from contracting parties is necessary to enforce the seasonal closure within the coverage of CCAMLR. The paper concludes that the seasonal closure feasible under the CCAMLR legal framework, which, like the measures of MPAs, will facilitate the fulfillment of best scientific evidence and eventually contribute to the SDG-14 progressively in the Southern Ocean.