This study was conducted to investigate the effects of dietary conjugated linoleic acid (CLA) and oil containing unsaturated fatty acid supplementation on egg production and quality in laying hens. Two hundred-eighty eight, 36 week old ISA brown commercial layer, were employed in a 5 week feeding trial. Dietary treatments are 1) BO (basal diet + 1% soybean oil + 1% oat), 2) BS (basal diet + 1% safflower oil + 1% oat), 3) BF (basal diet + 1% free fatty acid + 1% oat), 4) CD (basal diet + 1% CLA containing diglyceride + 1% oat), 5) CT (basal diet + 1% CLA containing triglyceride + 1% oat) and 6) CP (basal diet + 1% CLA by-product + 1% soybean oil). For overall period, hen-day egg production was not significant among treatments (P>0.05). Egg shell breaking strength at 3 weeks in CP treatment was significantly lower than BS, BF, CD and CT treatments (P<0.05) and that at 4 weeks in BO and CP treatments was significantly lower than others (P<0.05). Egg shell thickness at 3 and 4 weeks in CP treatment was significantly lower than BS, BF, CD and CT treatments (P<0.05). Egg weight at 3 and 4 weeks in CP treatment was significantly lower than others (P<0.05). Yolk height at 4 weeks in BF and CT treatments was significantly highest compared to BO, CD and CP treatments (P<0.05) and among BO, CD and CP treatments, that in BO and CD treatments was significantly higher than CP treatment (P<0.05). At 4 weeks, yolk color in CP treatment was significantly higher than BO and BS treatments (P<0.05). Haugh unit at 3 and 4 weeks in BO and CP treatments was significantly lower than others (P<0.05). In conclusion, supplementing CLA and oil containing unsaturated fatty acid for laying hens improved egg shell breaking strength, egg shell thickness, egg weight, yolk height, yolk color and haugh unit.