Brassica napus L. (Brassicaceae) plantation has increased as its seed is the primary source for bio-diesels. This study was conducted Male sterile (MS) line (cv. 'Sun-Mang') to pollen parent (cv. 'Mokpo 64') ratio of rape plants on fatty acid compositions of six sequential stages and yield performances. Ratio of MS line to pollen parent was followed, 4:2, 10:1, and 10:2, respectively. Seeds of six sequential stages (35, 40, 45, 50, 55, and 60 days after flowering) were collected and determined using SEED FAME ESTIMATION. The results showed that oleic acid content (C18:1) of the MS to pollen parent ratio (4:2) relatively increased up to 60 days after flowering compared to other ratios. Other fatty acid compositions such as palmitic acid (C16:0), stearic acid (C18:0), linoleic acid (C18:2) and linolenic acid (C18:3) contents decreased during seed maturation period. Seed weight (1000 seeds) of MS to pollen parent ratio (4:2) was higher than other treatments. These results suggest that fatty acid compositions and seed weight was affected by ratio of MS line to pollen parent. For rape seed production, a suitable ratio of MS line to pollen parent will be required to cultivate rape plantations.