The population structures of three stands of red beech forest in the N.W.Ruahine Range are described. Seedling establishment, growth and survival is studied by means of tagged seedlings in permanent plots. Three microsite types are identified, the rotting wood microsite being the most favourable for seedling growth and survival. No seedlings survive under the extensive fern layer. Light compensation points for 1st year seedlings are 1.9% and 3.9%. Light intensities in some microsites are below the compensation point. Seedlings have established at least every 2-3 years in the past and seedling establishment is not solely dependent on the occasional mast seed years. A model combining estimates of densities, survival rates and mortality rates predicts that the size of the seedling population will be maintained. Regeneration appears to be effective only in the ridge-top stand. Large canopy gaps containing few saplings and seedlings occur in all stands. Seedling numbers are limited by the availability of suitable microsites and this in turn reduces the rate of regeneration.