《民法典担保制度司法解释》第70条对保证金账户质押的设立规则作了修正，增加了债权人实际控制账户、资金浮动、用于担保目的等表述，删除了特定化的要求，回避了这一制度的动产质押性质。新规范引领保证金账户质押的新实践，这些表述变动的内在逻辑需要探讨，以减轻法律规范表述模糊造成的制度误解。在保证金账户质押标的的性质上，本文认为保证金作为质押关系的标的物，本质上属于货币，当权利人没有转移所有权的意思表示，且保证金能价值特定的情况下，保证金的所有权不随交付转移，从而符合质押规则的要求。且保证金账户质押中不是债权质押，也不是让与担保，而应适用动产质押的规则。作为一种非典型担保，在适用动产规则时存在特殊性，需要参考浮动抵押制度、价值返还请求权学说，以解释保证金的“不特定”。在动产质押的基础上，本文着重对《民法典担保制度司法解释》第70条的表述变化展开讨论。在“专门”的账户和资金浮动上，原本的“特定化”在实践中难以为继。专门的保证金账户在担保功能上特定，以配合债权人“实际控制”账户，区分担保财产与一般财产。账户款项的浮动无需对应所担保债务的变动，只受质押合同约定及债权人同意的约束。在实际“控制”账户的问题上，将控制解释为占有的一种变形，重点在于债权人对账户的支配权，债权人直接或间接控制账户均能满足质押设立的要求。“控制”作为公示方法存在隐蔽性，可以通过外部标识、通知特定第三人、登记保证金账户来加强公示力，登记可以作为保证金账户的对抗要件。在保证金账户质权的优先受偿问题上，直接划扣账户款项不属于流质约定。保证金账户质押有物权效力，可以对抗一般债权人的执行申请。允许法院冻结账户，但一般不能直接划扣账户资金。优先受偿的范围不能超出所担保债权的数额，账户内超出约定额度资金的性质可由当事人在质押合同中约定。关于保证金在破产中的归属问题，债权人可以对破产债务人行使别除权而受偿保证金。在银行破产程序中，保证金不能被视为银行存款债务而清偿，应当认定其为独立于一般存款的质物，债务人履行债务后可取回保证金。

Article 70 of the Judicial Interpretation of the Civil Code on the Guarantee System revises the establishment rules of pledge of security deposit account, adding the statement that the creditor actually controls the account, funds floating, and security used for the purpose of guarantee, also blurting the nature of pledge of movable property and deleting the specific requirements. It is necessary to discuss the inner logic of these changes in order to alleviate the institutional misunderstanding caused by the vague expression of legal norms.In terms of the nature of the pledged object in the security deposit account, this paper believes that the security deposit, as the object of the pledge, is essentially currency. When the right holder has no intention to transfer the ownership and the value of the security deposit is specific, the ownership of the money will not be transferred with the delivery, so as to meet the requirements of the pledge rules. Guaranty is neither creditor's right nor assignment guarantee in pledge, but should apply the rule of chattel pledge. At the same time, as a kind of atypical guarantee, there is particularity in the application of chattel rules, so it is necessary to refer to floating mortgage system and the theory of value return to explain the "non-specificity" of security.On the basis of the nature of chattel pledge, this paper focuses on the discussion on the expression of article 70. In the special security deposit account and the floating of funds, "specific" is not appropriate in the practice of security deposit account pledge. Specialized security accounts are specific in their security function to match the creditor's "actual control" of the account, distinguishing secured property from general property. Fluctuations of account amounts need not correspond to the guaranteed debt, but are only subject to the pledge contract and the consent of the creditor. On the problem of "control", the control is interpreted as a form of possession, the emphasis is that the creditor has the right to control the account funds, and the creditor's direct control or indirect control can meet the requirements of the establishment of pledge. As a method of publicity, "Control" looks private. Publicity can be strengthened by external identification, notification of specific third parties and registration of security deposit accounts. Registration can be used as a confrontation element for security accounts. As for the priority of payment of pledge right of security account, directly debiting the money in the account is not a exile agreement. The pledge of security deposit account has the effect of property right, which can oppose the application of execution of common creditors. The court is allowed to freeze accounts, but generally cannot directly deduct funds from the accounts. The scope of priority for compensation shall not exceed the amount of the obligatory right secured, and the nature of funds exceeding the agreed amount may be stipulated by the parties in the pledge contract. In bank bankruptcy proceedings, the security deposit cannot be regarded as a bank deposit debt to be paid off, and it should be recognized as a pledge independent of general deposits, and the debtor can get back the security deposit after fulfilling the debt.