Objective To investigate the status quo and factors associated with advance care planning (ACP) readiness in hospitalized elderly patients with chronic diseases，and to provide reference for the implementation of ACP in clinical practice. Methods A total of 247 hospitalized elderly patients with chronic diseases were selected from 3 Class A tertiary hospitals and were investigated using the ACP Readiness Scale, the Family Support Scale and the EuroQol Five-dimensional Questionnaire (EQ-5D-5L). Results The median(P25，P75) score of ACP readiness in this sample was 81.00(72.00，87.00). The score of ACP readiness was positively correlated with the total family support score and the health-state values measured using the EQ-5D-5L(both P<0.05). Multiple linear regression analysis showed that permanent residence, family support and the health-state values were the main influencing factors of ACP readiness in hospitalized elderly patients with chronic diseases (all P<0.05 for all)，which could explain 47.5% of the total variance. Conclusion Hospitalized elderly patients with chronic diseases report a medium to relatively high level of ACP readiness. It is suggested to strengthen ACP education for rural patients and encourage patients to obtain more family support to further improve their ACP readiness.