Where the guarantor is defrauded of the guarantee by the debtor and the creditor, he may collect evidence of collusion between the creditor and the debtor, including personal evidence, material evidence, audio-visual evidence, etc.
 According to Article 63 of the Civil Procedure Law, evidence includes: (1) statements of the parties; （2） Documentary evidence; （3） Physical evidence; （4） Audio-visual materials; （5） Electronic data; （6） Witness testimony; （7） Appraisal opinions; （8） Record of inspection. Evidence must be verified before it can be used as the basis for ascertaining facts.
 How can the guarantee agreement be effective? The guarantee agreement will take effect only after the guarantor's name, guarantee amount, guarantee method (general guarantee or joint guarantee), signature or seal are written. If there is no above content, the security agreement will not be effective, so the secured loan will not recognize such a security agreement. After the guarantee agreement comes into effect, the guarantor shall bear relevant responsibilities according to the requirements of the agreement. To sum up, after the guarantee agreement takes effect, the lender pays off the debt, and the guarantee liability is not terminated immediately. The guarantor needs to bear the guarantee liability for a period of time from the date of expiration of the loan term. Do you understand?
 Article 63 of the Civil Procedure Law includes:
 （1） Statement of the parties;
 （2） Documentary evidence;
 （3） Physical evidence;
 （4） Audio-visual materials;
 （5） Electronic data;
 （6） Witness testimony;
 （7） Appraisal opinions;
 （8） Record of inspection. Evidence must be verified before it can be used as the basis for ascertaining facts.