wants to build A Micro Quad with this motor.
any comment..
http://www.rcbazaar.com/products/1915-avionic-m181817-kv4500-micro-brushless-motor.aspx

It depends on the AUW of your quad.

Yes you can , AUW has to be kept between 250-350gms for agile flight, but why did you zero in on these motors.
I had used different avionic motor for my quadcopter, had heating/efficiency issues.Now many of them make noises.

http://www.rcbazaar.com/products/1913-avionic-m222625-kv1800-micro-brushless-motor.aspx

ok weight is the main issue, i like this motor only due due its small size and weight i wants to build a micro quad....and about efficiency...i m just working on VTOl twincopter i m facing the same issuewith avionic motors

Well its upto you, can use the motors. Go for a 10/12 amp esc, dont think 20 amp would be necessary.Use smaller props if you want longer life out of the motors, which will again push you to reduce weight.
You will have to go through some trials and errors to get it working in the end.