OBJECTIVE To develop a questionnaire of the Knowledge-Attitude-Practice （KAP） for patients receiving oral anticoagulant therapy. METHODS Under the guidance of the theory of KAP， literature analysis and interview method were used to design the initial KAP questionnaire for patients treated with oral anticoagulants. Delphi method was adopted to consult the initial questionnaire and modify the questionnaire based on expert suggestions to form the final questionnaire. RESULTS Two rounds of consultation were conducted with 18 experts， and 18 questionnaires were sent out and recovered in each round， so the positive coefficient of experts was 100%. The expert authority coefficient was 0.94. The average importance scores for all dimensions， factors， and items of the questionnaire in both rounds were ≥4 points. The coefficient of variation was ≤0.25. The Kendall’s concordance coefficient for the overall questionnaire and the three dimensions of knowledge， attitude， and practice ranged from 0.09 to 0.34 （all P＜0.05）. Following the first round of expert consultation， four items were modified， two items were deleted， and five items were added； after the second round of expert consultation， ten items were modified. The final version of the questionnaire included three dimensions （knowledge， attitudes， and practice）， 17 questionnaire factors， and 40 items. CONCLUSIONS The questionnaire has high reliability and scientific validity with relatively concentrated expert opinions. It is suitable for assessing the knowledge， attitudes， and practice status of patients receiving oral anticoagulant therapy.