Public. According to official website of Mianyang Education Bureau, Sanjiang Experimental School in Mianyang Economic and Technological Development Zone is a public school. It is a public nine-year compulsory education school led by Mianyang Nanshan Middle School, a century-old prestigious school, and founded by Economic Development Zone. The school is rooted in Nanshan's centuries-old and heavy tradition of running a school, adhering to the famous school gene of "patriotism in reading, patriotism in reading, diligence and frugality, seeking truth and being pragmatic".