In South Kalimantan, nira of palmas is processed become compact sugar, liquid sugar processing is extremely rare to be done. Producing liquid sugar means succinct the sugar use and eliminate the energy need for crystallization or compaction. The aim of this research is to observe the preservation duration of the liquid Sugar produced. Nira of Sugar palm is taken from Takisung Village of Tanah Laut Regency, we test 3 levels of natrium benzoate concentration, they are A (Control), B (0,05 % or 0,07 gr) and C (0,10 % or 0,14 gr). The observation take one and a half month for monitoring (45 days). The result shows that the liquid sugar can preserved in 25 days for A treatment, thus because in 26th day the sample is contaminated by fungi and the flavour become acidic. Hence, B and C treatments are well-preserved, there are no colour and taste changing, also no fungal contamination. Modification of liquid sugar processing in this research purposed to increase the efficiency as a strategic effort in producing more qualified, economical and practical Sugar for use. Therefore, liquid sugar has a potential market prospect locally or regionally. Keywords: natrium benzoate, preservation, liquid sugar