I want know about long hair for man is it Haraam or not by the way I didn't cut my hair 3 years ago.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

There is no harm for a Muslim to keep long hair, and his hair should be like the hair of the Prophet . Al-Baraa' narrated that the hair of the Prophet used to reach down to his shoulders and ear-lobes. However, if a Muslim keeps his hair long, he should not do so as a fashion, or as a lack of manliness, or to imitate dissolute people and the like. One must also wash it, oil it, comb it, etc… The Prophet said: "Whoever has hair, he should care for it." [Abu Daawood]. 

Allaah knows best.