There is judicial chaos in the determination of community debt, which is due to the value orientation deviation of the property contract attribute of civil and commercial rules to replace the marriage dispute consideration rules of common life, breaking through the relativity of contract and over protecting creditor's rights. It is urgent to take the traditional comparison of Chinese and western law as a mirror to trace the origin.The debt borrowed by husband and wife in the community debt is different for the sake of the legitimate purpose of marriage in accordance with ethics and jurisprudence, thus forming the identification principles with different characteristics. The absorption principle under the cohabitation and common estate in ancient China is quite different from the separation principle based on consciousness autonomy in Roman law, but converging the principle of common life. The principle of absorption which can hardly have chances to develop endogenously is conducive to marriage stability; while the principle of separation which is easy to swing too far with the tremendous governance cost respects individual independence. Therefore, fundamental issues from identification of community debt can be solved by the philosophy of achieving properness and harmony, the establishment of a system to prevent the risk of creditor's rights, and the implementation of the judicial discretion to the interests of the vulnerable group.