The hypoglycaemic effect of water soluble polysaccharide (WSP) extracted from gembili tuber was studied in this experiment. Extracts from three different methods, an aqueous (water-WSP), papain assisted (papain-WSP), and tempeh inoculum assisted (tempeh-WSP) extractions, were compared. The effects were evaluated by means in vivo test on hyperglycaemic-induced rats by performing the so called blood glucose response, followed by in situ glucose absorption test and short chain fatty acids (SCFA) analysis. A nested experimental design was employed in the experiment. All the three extracts reduced the blood glucose level. The effect of tempeh-WSP extract was comparable to that of the papain-WSP extract, but was not signicantly different from the water-WSP. However, the water-WSP extract tended to have a weaker effect than that of the other extracts. Similar result was found on the SCFA level. The highest SCFA level was found on the rats treated with tempeh-WSP extracts. It was likely that the hypoglycaemic effect of the tempeh-WSP extract was the best.