Can SMS content be used as the main evidence of arrears?

Two years ago, I lent my high school classmate Yang 30,000 yuan, and there was no IOU. He promised to pay back the money as soon as possible. Over the past two years, I have repeatedly sent messages to Yang who works in other places to urge him. At first, he always replied that he wanted me to give him some time. I paid attention to these messages and left them behind. I texted him again recently, but he didn't reply. I'm worried that Yang will default, and I want to change it to Sue, but I don't have an iou. I wonder if I can win the lawsuit. Excuse me, can I use dunning SMS to recover the arrears? Reader Liu Qiang Liu Qiang Reader: Judging from the situation you reflected, since China's Civil Procedure Law stipulates the principle of "whoever claims, who gives evidence", if the prosecution requires Yang to repay, it should give evidence to prove the facts on which this claim is based. Now, you want to use SMS as evidence to prove the fact that Yang borrowed money from you. According to Article 7 of China's Electronic Signature Law, "a data message shall not be refused as evidence just because it was generated, sent, received or stored by electronic, optical, magnetic or similar means." According to this, the message between you and Yang Can can be used as evidence. However, short messages can be used as evidence, which does not mean that short messages alone can prove the loan relationship. You should at least collect the following evidence: the mobile phone that sends the dunning text message is yours; The mobile phone that replies to the SMS is owned by Yang; The content of Yang's reply message has the meaning of promised repayment; Send and receive text messages at the same time and with coherent content. In addition, in order to ensure the validity of the evidence, you'd better notarize the short message, because the data message evidence is easy to be tampered with, and the court will often be very cautious when determining legal facts only by data message evidence. In order to prevent Yang from breaking the contract, I suggest that you try to collect some indirect evidence, such as the testimony of witnesses who know that Yang borrowed money from you. And form a set of evidence chain to prove the establishment of the loan relationship between you and Yang, so as to ensure winning the lawsuit.