which direction is good to keep the bed OF master bed room

You have not mentioned the direction of the master bedroom yet according to vastu,  a master bedroom should be located in southern part home and all other bedroom should be located in south-west of the home.

As far as bed concern, it should be of good quality wood and metal bed should be avoided. Place the bed in master bedroom in a way that the foot side of the bed should be in North and does not face the door. Do not place bed in corner or under beam.

Still if you need more info or have any doubt, ask a vastu consultant to visit your home and advise you as per your home location and may suggest other remedies.  

Regards 

the best direction to keep bed in master br or other rooms is towards south west the head while shall remain in south. the bed should not be visible in mirror while sleeping.

Er. p.a.lalwani

pldesignhome1969

The Head should be towards South or East while sleeping.