Sago palm (Metroxylon sagu Rottb.) that stores a large amount of starch in the trunk is an important staple food in some area of Southeast Asia and South pacific (Ehara et al. 2000). This palm is one of the dominant species in tropical swampy, alluvial and peaty soil which are generally severe acidity and almost no other crops can grow without drainage or soil improvement. Yamamoto (1996) reported that sago palm is not found in peaty soil in its natural habitat, but it has the mechanism to adapt well in peaty and swampy areas. It is considered to be acid tolerant, however, there are few studies on the mechanisms of acid tolerance in sago palm. Thus we investigated the effect of pH in the growth media on growth and nutrient absorption of sago palm to evaluate the tolerance ability under low pH conditions. Materials and Methods Nine seedlings at the 7th leaf stage were transplanted in a 1 / 5,000a Wagner pot that filled with vermiculite and Kimura B culture solution with different pH conditions (pH 5.7, 4.5, 3.6) with 3 replications. The pH of the culture solution was adjusted with 1.0 N HCl as required. Culture solutions were changed every 2 days. An air pump connected into the pots to provide air for roots. The number of new emerged leaves, the SPAD value, plant length, photosynthetic rate, transpiration rate and stomatal conductance were measured for 5 mounts. At the end of the treatments, green leaf number, leaf area, fresh weight, dry mater weight, chlorophyll content of leaflets and ion concentration of the 3 parts (leaflet, petiole and root) were measured. Results and Discussion There were no significant differences in the dry matter weight of all the 3 parts (leaflet, petiole and root), weekly increment of plant length from 19th to 20th week and the total leaf area between the three pH treatments (Table 1). A new leaf emerged and the number of green leaves was same between the three pH treatments which meant that the low pH conditions did not affect the new leaf emergence and leaf senescence. The differences in SPAD value and specific leaf area (SLA) of leaflet at different leaf positions were negligible (Fig. 1). The photosynthetic rate, transpiration rate and stomatal conductance of the 4th leaf position from the top were also not significantly different between the three pH treatments (Fig. 2). The P concentration in the top parts (leaflets and petiole) slightly decreased under lower pH conditions (Fig. 3). Contrarily, the P concentration in both the stele and cortex of roots increased under lower pH conditions (Fig. 4). However, the difference in P concentration in the whole plant between the three pH treatments was not significant. The P translocation from the roots to top parts might be affected by the low pH. The Al concentration in leaflets increased under lower pH conditions in all the parts and at almost all the leaf positions (Fig. 5). From these results, we concluded that sago palm can tolerate even at pH 3.6 for 5 months in the growth media even the P translocation is affected.