Head of ballpoint pen as well as ballpoint pen connector and ballpoint pen refill adopting same

The invention discloses a head of a ballpoint pen, which comprises a point of the ballpoint pen and a ball which is arranged in the point of the ballpoint pen and can roll. The point of the ballpoint pen comprises a ball accommodating slot, a main ink supplying pipe, at least one ink communication channel and a ball limiting device; the ink communication channel is arranged between the ball accommodating slot and the main ink supplying pipe and used for communicating the ball accommodating slot with the main ink supplying pipe; and the ball limiting device is arranged on the ball accommodating slot and used for preventing the ball from sliding out of the ball accommodating slot. The invention further discloses a ballpoint pen connector and a ballpoint pen refill which both adopt the head of a ballpoint pen. Because the head of the ballpoint pen is made of plastic, the head of the ballpoint pen is environmental friendly. In addition, because the head of a ballpoint pen is made by injecting and moulding the pla