Objective To investigate rules of heartwood formation and essential oil distribution of Indian sandalwood, Santalum album, plantation in Hainan, and provide reference for development of sandal plantation in large scale in China.

Method The presence of heartwood, heartwood proportion, and the distribution of essential oil content and composition of 21-year-old sandal plantation in Jianfeng mountain, Hainan were surveyed by random sampling.

Result The heartwood had formed naturally in all sampled sandals. The average heartwood diameter, heartwood proportion and essential oil content at 30 cm above ground were 10.14 cm, 38.01% and 4.36%, respectively. There was positive linear correlation between ground diameter and heartwood diameter (r=0.873), but no clear correlation was found between ground diameter and heartwood proportion (r=0.279). The distribution of essential oil was not significantly different among different azimuths including east, south, west and north(P=0.197), but was significantly different among different radial positions (P < 0.05). The essential oil content in sapwood was significantly lower than that in heartwood. Totally 56 constitutes were isolated from the essential oil, of which 42 were identified. Although the number of constitutes in the essential oil extracted from heartwood was less than that from sapwood, the oil quality of heartwood met the ISO standard (ISO3518:2002) for S. album oil while the oil quality of sapwood did not.

Conclusion Hainan is considered as a suitable region for sandal growth given the good growth performance, high heartwood proportion and essential oil content.