http://www.hongkongairport.com/eng/aguide/baggage.html

Left Luggage

A secure left luggage service, including short-term luggage storage is available inside the Meeters and Greeters Hall. It opens 24 hours a day from Tuesday to Friday. For the rest of the week, it operates from 06:00 hours in the morning to 01:00 hours after midnight.

LEFT BAGGAGE RATE HK$ / Price
Up to 3 hours $35
3 hours to 24 hours $50
24 hours to 48 hours $120
Thereafter each subsequent 24 hour period or part thereof +$80

"Out of Gauge" baggage (exceeding any part of the dimensions 85cm (L) x 29cm (W) x 85cm (H) or exceeding 30 kg) shall be charged at least double the normal rate or by the number of times that the longest out of gauge dimension / weight exceeds the standard or part thereof.

"Left Baggage" reserves the right to request a cash deposit.