This article decides as “A Study on Buddhism Mind-Consciousness, Practical Theory and Karma System” ,Therefore, in the scope of the study will be used “Mind-Consciousness ” as the core to carry out all the connotation of “ Mind-Consciousness ”. In the analysis of content, including the relationship between the "Mind-Consciousness" and "Eight Consciousnesses", the relationship between the "Transformation of the Basis" and "Tathāgatagarbha ", also relationship between the "Buddha" and "Root of life force" , and investigate the "Buddha" how "Karma System" in the operation, and the relationship between "Buddha" and "Transmigration ". In the this article third chapter, will be analyze "Mind-Consciousness" and "Physical universe" and "Ten Dharma Realms" the relation among the three , And to investigate the "Mind-Consciousness" of How to Principle of creation of the universe, And to investigate the "Karma System" and " Causal laws" In the "Cosmology" Position. In the fourth chapter, we will discuss the relationship between "core knowledge" and "state" relationship, Including the "Mental Condition" when "Mind-Consciousness" generated for the Causes of action and principle, Meditation and sleep will have the principle of the "image". In the fifth chapter, this article take "Karma System", "Causal laws" as a core, right "Practical Theory" the principle carries on a more thorough discussion. In short this paper " Mind-Consciousness " as the core throughout the full text, were carried out " Ontology ", " Cosmology " and how the role of " Epistemology " in the " Mind-Consciousness " in, and from analysis of " Causal laws " the principle of " karma theorem " , and " Causal laws ", " karma theorem " to Practical Theory more in-depth analysis.