Abstract Models are developed for estimating optimal growing stock levels and rotation ages for loblolly pine. Under a profit maximization goal, they provide for varying stumpage prices, stand ages, site indexes, stocking levels, alternative rates of return, and regeneration costs for two single-product objectives. Quality differential as expressed in stumpage prices is recognized. A system is also provided for determining optimal stocking levels at the same marginal rate of return as that selected for determining optimal rotation age. Using a loblolly pine growth study in the Southeast for the biological data, solutions of stocking levels at various alternative rates of return indicate that stocking standards for profit maximization are much less than levels which optimize physical production. Rotation age solutions indicated that rotations lengthened as the alternative rate of return is reduced, as the site index increased and as a quality differential is introduced. In general, the optimal rotation age is less flexible with changes in the variables affecting it than optimal stocking levels.