Is it illegal for me to sing in the street? I'm just entertaining myself, not making a profit?

First of all, it depends on what the content of this song is. Some content can directly constitute a crime. See Article 120 of the Criminal Law for details. If the circumstances are serious, he may be sentenced to fixed-term imprisonment of more than five years, fined or confiscated.

Then it depends on where to sing, in what form, whether there are other actions in the process of singing, and whether it affects the normal life around. This can be seen from the first section of the third chapter of the Public Security Administration Punishment Law.

It is not illegal to simply sing normally, but if the content of singing is illegal or singing in inappropriate occasions, it may constitute a crime of misconduct in the process of singing.

In addition, the Criminal Law and the Public Security Administration Punishment Law are the laws of the National People's Congress, which are common throughout the country. Specific to each place, there may be local laws and other regulations on street singing, so you need to consult the local laws and regulations library.