The purpose of this study is to describe the problem solving ability of students mathematis work PGMI based object ZPD primary school students, with a descriptive qualitative research methods. Insendental sampling using sampling at half PGMI student V. Data were collected through a test which is divided into two, namely the initial test and final test and through observation and interviews. With a simple statistical analysis results that students who have a high initial knowledge to solve problems working mathematis on objects of primary school students aged 6-10 years by ZPD, also have mathematis problem solving skills are good. While students who have a low initial knowledge unable to solve problems working mathematis on objects of primary school students aged 6-10 years by ZPD. Keywords. Early Knowledge, Zone Of Proximal Development (ZPD), Problem Solving