Pumpkin flour need to be modified for improving the characteristic. The purpose of this research is to study the effect of the lactic acid concentration and the soaking time to physicochemical characteristic of pumpkin flour which are : viscosity, swelling power, moisture content, reducing sugar, protein and β-carotene. This research using Factorial Randomized Design consisting of two factors which are lactic acid concentrations (0,5; 1 and 1,5%) and soaking time (30, 60 and 90 minutes) with three times replications. The result showed that the increasing of lactic acid concentration affect to increasing of viscosity, moisture content and reducing sugar; decreasing swelling power and protein; and inhibit degradation β-carotene of pumpkin flour significantly. The soaking time affect to increasing of viscosity and swelling power, decreasing protein and inhibit degradation β-carotene significantly, but it’s not have significant affected to moisture content and reducing sugar of pumpkin flour. Another research aims to to determine the influence of variation the long time submersion and the concentration of acetic acid used to the chemical characteristics (water content, sugar reduction, soluble protein and β-carotene content) and the physical characteristics (viscosity and swelling power) from yellow pumpkin (Cucurbita moschata) modified flour produced. This research applied Completely Randomized Design (CRD) consist of two factor which are the variation long submersion (30 minute, 60 minute, 90 minute) and concentration of acetic acid that used (0,05%, 0,10%, 0,15%) (v/v). The data then analyzed statistically by using Two Way ANOVA, if the results obtained there is a significance then followed by DMRT test with a significance level of 0,05. The result of the research obtained in analysis of chemical characteristic such as water content 10,37-11,73%, 23,46-50,94% sugar reduction, 702,25-1011,98 µg/g β-carotene, 4,15-5,89% soluble protein. The analysis of physical caracteristic such as viscosity in the amount of 585-44000 cP and swelling power in the amount of 11,17-18,09 g/g. From the result of the research can be concluded to modified pumpkin flour that it have influence interaction between concentration of acetic acid and long submersion, it is extend a significance about sugar reduction content, viscosity and swelling power. However, it isn’t extend a significance about water content, β-carotene content and soluble protein content. Higher concentration of acetic acid and long submersion will increase sugar reduction content, viscosity and swelling power. These researches were conducted by Anjar Triyani and Yanuwardana  from Department of Food Science and Technology UNS, under supervision of Ir. Basito, M.S and Dimas Rahadian A.M, S.TP, M.Sc. This article is also published in Jurnal Teknosains Pangan Vol II No 2 April 2013. It also can be downloaded in fullpaper via