Konjac extract is also known as glucomannan. This bulk-forming laxative is a form of dietary fibre, purported to make stools bulkier and larger so they're easier to pass. Konjac extract is not a necessary nutrient and is used purely as a supplement. Konjac is a kind of perennial herbage plant with low energy, low protein, and high fibre, glucomannan is the main component of konjac. Konjac contains more than ten kinds of amino acid required by the human body, microelement and unsaturated fatty acid, it is effective in tumour resisting, blood health keeping and weight-losing. It also has some physical-chemical properties such as water-soluble, fresh-keeping, thickening, stabilization, suspension, gelling, binding , it is not only one kind of natural food additive but also one kind of ideal assistant healthcare food, it is recommended by WHO as one of the best healthcare foods for human being in 21 century.