The quality of porcine semen deteriorates very rapidly during the semen preservation process. The aim of this study is to find alternative diluents for Duroc semen preservation by changing different semen diluents. Two Duroc pigs, ± 3 years old, were trained twice weekly for semen collection. Immediately after collection, sperm were examined macroscopically and microscopically. Semen with sperm motility ≥ 70%, sperm concentration ≥200 x 106 cells/ml, and abnormality ≤20%) was diluted with six diluents, namely: Beltsville Thawing Solution® (BTS), Durasperm, Citrate Egg Yolk (CEY), Tris Egg Yolk (TEY), CEY + Olive Oil (CEYO) and TEY + Olive Oil (TEYO) in the ratio of one part semen and four parts diluent. The liquid sperm was stored at 18-20 oC and examined every eight hours for 80 hours. The result shows that sperm motility, viability and plasma membrane integrity of Duroc semen with CEYO and TEYO are comparable to BTS. No significant difference was found in sperm abnormalities. The results suggest that citrate egg yolk and Tris egg yolk in combination with olive oil are suitable as alternative diluents for the preservation of porcine sperm. Further studies are needed to determine the most suitable olive oil concentration for the preservation of porcine sperm of different breeds.