I reach hong kong airport around 12midnight.. What is the best way to go to rambler garden hotel at tsing Yi?

Taxi is the best way. As well as that, you can also take shuttle bus to travel. Take bus no. N31 to CHEUNG ON BUS TERMINUS, where transfer to no. N241 to get off at CHING TAO HOUSE CHEUNG CHING ESTATE, which is within several minutes's walking distance from your hotel then.

Thanks irena for your advise..

But how much the taxi cost after midnight from airport to rambler garden hotel?

the taxi fare would be around 180HKD.
The buses I suggested above are overnight buses by the way.

Thanks..