. Ridwan, H.K., Nurmalinda, Sabari, and Y. Hilman. 2010. Financial Analysis of Potato FarmingSystem Using G4 Certified Seed to Improve Potato Farmer's Income. The main problem on potato farmingsystem was low productivity (16.94 t/ha). The use of certified seeds (generation four/G4) was expected to improveproductivity and potato farmers income. The research was conducted at Pangalengan District, Bandung, West JavaProvince and Batur District, Banjarnegara, Central Java, from January to December 2008. The objectives of thisresearch was to analyze financially the used of certified seed (G4) in term of production cost, productivity, revenue,and profit of potato farming in comparation with the used of uncertified seed. The study was conducted by usingsurvey method. Primary data were obtained through interviewing farmers and secondary data were collected fromthe related institutions. Qualitative data were analyzed descriptively, while the cost and income analysis weredone by static method, and t test. The results indicated that the production cost in Pangalengan reached as much asRp37,042,970.00/ha (using certified seeds) and Rp29,305,108.00/ha (using uncertified seeds). Similar result wasobtained in Batur, the production cost was Rp23,718,196.00/ha (using certified seeds) and Rp22,589,475.00/ha (usinguncertified seeds). In Pangalengan, potato productivity reached 26,364 kg/ha (using certified seeds) and 22,001 kg/ha (using uncertified seeds), while in Batur, the productivity was about 16,976 kg/ha (using certified seeds) and14,031 kg/ha (using uncertified seeds). The result of input and output analyses showed that in Pangalengan, potatofarming provide revenue and profit about Rp.70,417,354.00 and Rp.33,374,384.00/ha/season respectively (usingcertified seeds), while uncertified seeds gave revenue and profit Rp.53,529,785.00/ha and Rp.24,224,677.00/ha/season, respectively. Whereas in Batur, the use of certified seeds provide revenue and profit Rp.67,130,010.00 andRp.43,411,818.00/ha/season respectively, while uncertified seeds provide Rp.51,338,645.00 and Rp.28,749,170.00/ha/season respectively. The results of t-test showed that in Pangalengan, the use of certified seeds was significantlydifferent in term of production cost and revenue, while in Batur, there were a significant different on the revenue andbenefit between the use of certified and uncertified seeds.