Abstract: The reserve siteselection problem is how to minimize the cost of the reserve system while satisfying certain conservation goals. To solve this problem, simulated annealing algorithm is widely used. Take the Great Blue Mountain World Heritage Area (GBMWHA) as an example, this paper studied the distribution of myrtacea in the 100 kilometers buffer area of GBMWHA. The aim is focused on the compactness of the reserve system. We experimented variety parameters of the objective function，namely the boundary length modifier (BLM). The results show that, a more compact portfolio could be achieved at the expense of larger area. But the compact system has shorter boundary, thus is easier to manage.

Key words: simulated annealing, BLM, myrtacea, compactness, the Great Blue Mountain World Heritage Area, simulated annealing, BLM, myrtacea, compactness