Although assisted reproductive technology (ART) currently exists, the only embryo preservation technology that is available is cryopreservation. In the present study, small molecules were used to hold embryos at room temperature. The basic medium for embryo holding for a short period of time at 4 °C, 10 °C and 20 °C consisted of 1% BSA non-cryopreservation medium (BNC) instead of fetal bovine serum. To maintain survival and prevent damage during embryo incubation, three candidate small molecules were selected-CHIR99021, Y-27632 and Thiazovivin-and their concentrations were optimized. The viability and hatching rate of embryos incubated at 10 °C were greater for Y-27632-BNC and CHIR99021+Y-27632-BNC compared to BNC. However, the rate was lower for Thiazovivin-BNC compared to BNC. Although there were no surviving embryos after incubation at 20 °C, the viability and hatching rate of embryos significantly increased in Y-27632-BNC and CHIR99021+Y-27632-BNC compared to BNC. The pregnancy rate of embryos incubated at 20 °C was also greater in the CHIR99021+Y-27632-BNC group compared to that in the frozen group. The mechanism by which small molecules enhance survival of embryos during incubation was investigated, and expression of heat shock protein 70 was observed to increase. The findings of this work may be useful in improving ART in the agricultural field.Cattle are one of the most important livestock in the world. Their reproduction constitutes a large part of the agricultural economy in many countries including milk and meat. Considering this point, it is essential to use and develop assisted reproductive technology (ART) such as artificial insemination, embryo transfer (ET) and embryo production by in vitro fertilization (IVF) in this species 1 . However, most ART has focused on improving embryo production, genetic selection and pregnancy rates, while embryo storage has not received as much attention. In numerous instances during ART, embryos require storage for short or long periods of time. Cryopreservation with liquid nitrogen (LN 2 ) is generally used for long-as well as short-term embryo storage. However, physical damage is caused during the freeze-thaw process and the damage can limit embryo survival 2 . Thus, only high degree (high quality) embryos that can endure physical damage are normally used, while the rest, even though they still have the potential for full development, are mostly discarded. Moreover, freezing-induced damage reduces pregnancy rates either directly or indirectly 3 . Therefore, it is necessary to improve storage systems to improve ART efficiency.It has been reported that many cells, including embryos, can be stored at hypothermic temperatures 4, 5 . Recently, it was also documented that bovine embryos could be incubated for 7 days using a simple medium including FBS and that embryos incubated in the medium were able to develop into normal calves 6 . However, the low-temperature embryo holding protocol still had limitations including temperature tolerance, preservative quality, mobilit...