Legal analysis: If the signature is authentic and the content of the IOU is false, the validity of the IOU cannot be determined unless there is evidence to prove the fact of the loan. The essence of the distribution of the burden of proof is that the parties should claim which facts in the case, and thus bear the burden of proof for the fact claim.

Legal basis: "Criminal Law of the People's Republic of China" Article 266 Whoever defrauds public or private property, if the amount is relatively large, shall be sentenced to fixed-term imprisonment of not more than three years, criminal detention or surveillance, and shall also be sentenced to or A fine shall be imposed alone; if the amount is huge or there are other serious circumstances, he shall be sentenced to fixed-term imprisonment of not less than three years but not more than ten years, and shall also be fined; Imprisonment or life imprisonment, and a fine or confiscation of property. If this law provides otherwise, the provisions shall prevail.