AbstrakVitrifikasi merupakan suatu teknik kriopreservasi tanpa disertai pembentukan kristal es, baik intraseluler maupun ekstraseluler. Tingkat keberhasilan vitrifikasi sangat dipengaruhi oleh jenis dan konsentrasi krioprotektan yang digunakan. Sukrosa merupakan krioprotektan ekstraseluler yang mempunyai peranan dalam menjaga kestabilan membran sel pada saat proses dehidrasi. Tujuan penelitian ini adalah mengkaji efek penambahan sukrosa dalam dua level konsentrasi yang berbeda pada morfologi dan persentase hidup oosit pascavitrifikasi dengan menggunakan oosit domba yang telah dimatangkan secara in vitro sebagai model. Comparison of Oocyte Viability after Vitrification with Two Different Sucrose Concentration Level AbstractVitrification is a cryopreservation technique without the formation of ice crystals, both intracellular and extracellular. The success of vitrification depends on the type and concentration of cryoprotectants. Sucrose is one of the extracellular cryoprotectants that play a role in maintaining cell membrane during dehydration process. The purpose of this study was to examine the effect of the addition of two different sucrose concentration levels on the morphology and viability of oocyte after vitrification using matured sheep oocytes as a model. This study was conducted at the Research and Biotechnology Laboratory, Faculty of Animal Husbandry, Universitas Padjadjaran during September-December 2016. The oocytes were randomly assigned into groups with two different concentrations of sucrose in vitrification media: i.e. 0.5 M and 0.65 M. The parameters observed were the percentage of live oocytes and the dead oocyte morphology after vitrification-thawing. The results showed that the percentage of live matured oocytes post-vitrification increased by 20% after the addition of 0.65M sucrose. Fracture of pellucida zone was the major finding in the post-vitrification dead oocytes in 0.5 M sucrose group. This indicates that vitrification using 0.65M sucrose as extracellular cryoprotectant presents a higher oocyte survival after vitrification-thawing. [MKB. 2017;49(4):252-8]