Is it legal for lawyers to ask for 20% property fee?

Legal. According to the provisions of Article 44 of the Measures for the Administration of Lawyers' Practice, when a lawyer undertakes business, the law firm shall collect the lawyer's fees and related handling fees from the client in accordance with the regulations, and shall not collect fees without permission, and shall not accept property or other benefits from the client. Therefore, it is legal for lawyers to ask for 20% property fees. The fees for lawyer services with market-regulated prices shall be determined by the law firm through consultation with the clients.