One of the efforts to increase rice yield is through hybrid rice production. Hybrid rice has now been commercialized in Indonesia. The parental lines of the hybrids developed in Indonesia mostly came from introduced lines. Those lines were more susceptible to stresses, especially to pests and diseases, that make the yield of the hybrid fluctuated and wasn&rsquo;t stable. Hence, it is needed to develop hybrid variety using Indonesian parental line which were well adapted to Indonesia. Therefore, identification of those lines is needed. In the last four seasons 2000/01 WS until 2002 DS, 1471 lines have been test-crossed in Muara experimental station, Bogor. Out of 2769 hybrids developed from 1471 parental lines, 18.1%, 74.5%, and 7.1% were fertile, partial fertile or partial sterile and sterile, respectivively. The frequency of fertile plants tested in the observation yield trail was 3.4% and only 0.7% of sterile plants were continued in the backcross program for new cytoplasmic male-sterile line development. Several number of lines identified as restorer lines were progenies of popular variety, namely IR64 and IR36. While those six lines which identified as maintainer line came from crosser of Ptb 33 and IR3043.