The inferred resource is up 90% to 373.6 million tonnes at 0.31% copper, 58.5 grams per tonne molybdenum and 0.05gpt gold, using a 0.2% copper cut-off.
The resource had not been updated since May 2009 and takes into account additional drilling.
"We have undertaken a thorough re-evaluation of the Simuku project, incorporated the results of some deeper drilling underneath the previous mineral resource and we have been able to increase the inferred mineral resource from 200Mt to 374Mt, so this is an excellent result," Coppermoly managing director Dr Wanfu Huang said.
"Through the process of updating the mineral resource we have correlated our geological, geophysical and geochemical data sets and from this process identified a number of other porphyry copper-molybdenum-gold targets, which suggest that the current Simuku deposit could be one of a cluster of porphyry copper-molybdenum-gold systems on the overall Simuku project."
The Simuku resource remains open to the north, along strike and down-plunge.
An induced polarisation survey has identified several chargeability anomalies associated with sulphide occurrence.
Coppermoly had A$5.8 million in cash at the end of December, enough for about six quarters of activities.
Its main project is Mt Nakru, also on New Britain.
Coppermoly shares were up 40% to 0.7c, coming off a 52-week low of 0.5c.
