The use of non-certified seeds in rice farming in rainfed rice fields is still relatively high, around 60%. The objectives of this study (1) to analyze the comparison between the use of certified and non-certified rice seeds, (2) to measure the increase in the efficiency of input use and increase of profits with the use of certified seeds. The study was carried out in Semarang Regency, Central Java Province, Indonesian with a survey method. The data collected were analyzed descriptively using a comparison method between farmers who used certificated and non-certified seeds. The study's findings showed that the average productivity of rice using certified seeds was 5.41 tons/ha of dry milled grain, while the average productivity of rice using the non-certified seeds was 4.91 tons/ha. The profit obtained in rice farming using certified seeds was as much as 16,154,000.00 IDR per hectare, while the profit using the non-certified seeds was as much as 14,626,000.00 IDR per hectare. In rice farming using certified seeds, an R/C ratio of 2.81 was obtained, while those using non-certified seeds obtained an R/C ratio of 2.71. The study results showed that the use of certified seeds had increased the efficiency of input use and profits in rice farming.