I want Enemy rotate straight to Player. So, A Enemy Fire to Player

This is a common situation and I believe that if you had done some research, you would’ve figured it out yourself. Anyways, supposing that you want a smooth rotation, I recommend using Quaternion.Slerp() instead of LookAt(). A way to do this would be:

`public Transform Player;

private void Update()
{
Quaternion newRotation = Quaternion.LookRotation(transform.position - Player.position);
newRotation.z = Player.transform.rotation.z;
newRotation.x = Player.transform.rotation.x;
transform.rotation = Quaternion.Slerp(transform.rotation, newRotation, Time.deltaTime * 8);
}`

Since you did not tell, I assumed that you would like to rotate the enemy on the y-axis (note that the rotation on the z and x axis remain unchanged). This would work for both a 2D and 3D environment.