Abstract: Farmers are the main actor and direct participant in the conservation of agricultural heritage systems (AHS), so their cognition towards AHS conservation can impact their participation in AHS conservation, as well as the sustainability of the AHS. Farmers' cognition of AHS conservation reflects the current measures of AHS conservation and is important for policy makers to establish improved policies. However, at present, farmers' inadequate participation in AHS conservation due to limited cognition has become a common problem in most AHS sites. According to the available literatures and on-site investigations, local conservation of Anxi Tieguanyin Tea Culture System (ATCS) in Fujian Province, one of the China National Important Agricultural Heritage Systems (China-NIAHS), has faced similar problems. This study used structural equation modeling (SEM) to estimate the impact of farmers' cognition on their participation behavior in the conservation of ATCS in Fujian Province under the framework of the Theory of Planned Behavior (TPB). We divided the farmers' cognition toward ATCS conservation into three dimensions: their attitude toward the behavior (ATT), the subjective norm (SN), and the perceived behavioral control (PBC). In total, 209 households engaging in tea planting in Anxi County were interviewed and included in the analysis. Our results showed that ATT positively influenced the willingness to participate in ATCS conservation, but it was not significant (P=0.396). This was in agreement with the results of other prior studies. However, the SN and PBC had significant positive impacts on farmers' willingness to participate in ATCS conservation (P < 0.1%) and indirectly and positively impacted farmers' behavior to participate in ATCS conservation via the intermediary role of their willingness to participate in ATCS conservation. The indirect effects of SN and PBC on farmers' behavior to participate in ATCS conservation were 0.292 and 0.442, respectively. The ability to participate in ATCS conservation and the institutional environment of ATCS conservation were critical factors for farmers' willingness to participate. The ability to participate in ATCS conservation primarily comprised the mastery of professional knowledge and basic technology and the affordability of the time costs of participating. The institutional environment of ATCS conservation mainly involved the initiative of the village committee and the county government in carrying out ATCS conservation. The ATT, SN, and PBC had a significant positive mutual influence. ATT and PBC had the largest mutual effect (0.652). These results inform policy recommendations to further promote the conservation and development of AHS. The publicity of AHS conservation should be strengthened to enhance the level of farmers' cognition of AHS conservation. Various levels of government should establish AHS conservation system to construct a good institutional environment to increase the initiative of carrying out AHS conservation. It is also necessary to improve and implement incentive policies to enhance farmers' abilities of participating in AHS conservation.