Abstract: Important Agricultural Heritage Systems (IAHS) discussed in this paper, including Globally Important Agricultural Heritage Systems (GIAHS) designated by Food and Agriculture Organization of the United Nations (FAO) and China Nationally Important Agricultural Heritage Systems (China-NIAHS) designated by Ministry of Agriculture and Rural Affairs of the People's Republic of China (MARA), refer to the traditional agricultural systems with unique characteristics in economic development, ecosystem services, indigenous knowledge, folk cultures, and landscapes and/or seascapes, and having important significances in historical evolution and sustainable development of agriculture and rural areas. As of June, 2020, FAO has certificated 62 GIAHS sites from 22 countries and MARA has released five batches of 118 China-NIAHS sites which distribute in 28 provinces, municipalities and autonomous regions. At the same time, IAHS and their conservation have caused more and more attention from scholars in different fields. Based on the researches focusing on some important fields such as concept and connotation, features and values, application and management, conservation and development and so forth, a new cross-discipline is emerging. In this paper, 12 research priorities on IAHS concept, connotation and characteristics, 20 research priorities on IAHS conservation were put forwarded. At last, based on the experiences enrolled in the field, the author discussed three problems existing in the current IAHS research: "interpreting without real understanding" causing the neglect of the main connotation; "mountain-stronghold mentality" separating the research team; and "eager for quick success and quick profit" weakening the long-term research. To cope with these problems, some suggestions are advanced: Firstly, to clarify the concept, connotation and subject orientation of IAHS, and recognize its' systemic, compound, and living features for improvement of disciplines and research paradigm of IAHS. Secondly, to establish an academic community for IAHS research and conservation of experts from multiple disciplines, such as ecological, social, economic and management sciences so as to provide solid S & T support for IAHS conservation. Thirdly, to encourage the comprehensive research of IAHS through setting the National Key R & D Program and long-term collaboration among institutions and administrative departments so as to gradually establish IAHS research network.