According to reporter Ben Jacobs, Harto has negotiated personal terms with Chelsea and is waiting for an agreement between the clubs.
The deal is expected to be completed in the next few days, with the transfer fee likely to be around £40 million.
Hato is 19 years old and plays as left-back and central defender. His contract with Ajax will be until June 2028. The player scored 3 goals and 6 assists in 50 games last season, and the price of Deutschland was 35 million euros.