Won-Buddhist Mind Practice (MaeumGongbu) derives from the “method of applying the mind” (用心法) asserted by Sotaesan (1891-1943), the founder of Won-Buddhism. Since the popularization of ‘Jeong-Jeon Maeum-Gongbu’ (JJMP) in 1992, several issues have been raised about Won-Buddhist Mind Practice, and in this process it has come to coexist with the perspective held by those in the ‘On-Sam Maeum-Gongbu’ (OSMP) group. This study re-examines the principle issues of Won-Buddhist Mind Practice by comparing the viewpoints held by both JJMP and OSMP to show that these practice methods represent the ‘Sudden’ (頓)․‘Gradual’ (漸) viewpoints of Won-Buddhist practice methods. Until now, the issues dealing with the principles of Won-Buddhist Mind Practice have been dealt with in the chapter, The Essential Dharmas of Daily Practice, especially articles 1, 2, and 3. In this context, the ‘mind ground’ (心地) is typically used as a synonym for ‘self-nature’ (自性). And the emphasis on mind practice differs according to the interpretation of the ‘mind ground’ and ‘sensory condition’ (境界). First, advocates of the OSMP viewpoint define ‘mind ground’ in the narrow sense of Nature and divides Nature into that which is without discrimination and attachment, and Mind (which appears after discrimination). This method finds the causes of the functioning mind to start from ‘the dark thinking of sensory condition’, my inner tendency toward discrimination and a penchant toward attachment, rather than the ‘sensory condition,’ and deems the starting point of mind practice to be the awareness of ‘self-nature’ (自性), not the ‘sensory condition.’ As such, the OSMP can be understood as emphasizing the ‘Sudden’ aspects of mind practice. On the other hand, the JJMP stance defines ‘mind ground’ in a broader sense of Nature. This method understands the concept in dual terms of substance (體) and function (用), calmness (靜) and movement (動). This method accepts the appearing mind along the sensory condition as the action of truth, and argues that the starting point of mind practice is the ‘sensory condition.’ Therefore, the JJMP perspective can be understood as emphasizing the ‘Gradual’ aspects of mind practice. Moreover, we can consider the Cause and Effect (因果) of Won-Buddhism relevant to the scope of Mind Practice. Won-Buddhist Mind Practice has the aspects of ‘Re-arising Practice’ on the dimension of inner cause-effect and ‘Turning Mind’ on the dimension of outer cause-effect. These practices are included in The Essential Dharmas of Daily Practice. The purpose of this study is to investigate the range of available theories on mind practice and find the original intention of Won-Buddhist Mind Practice so that it can be applied on the level of the individual, human relations, society, and the environment.