This study was done with mouse embryo to assess effects of freezing media containing sucrose, freezing metods(1-F, 0.3$^{circ}C$/min;2-F, 3-5$^{circ}C$/min;3-F, 15$^{circ}C$min;4-F, LN2 vapour) and cell freezers on the embryo survival determined using the FDA test. The results are summarized as follows. 1. The FDA score obtained with 1, 2, 3 and 4-F was 3.8, 3.6, 3.2 and 3.2, respectively. There was a significant difference(P<0.05) between 1-F, 3-F and 2-F, 4-F. 2. The score at the morular stage(3.8) higher(P<0.005) than the blastocyst stage of embryos(3.2). 3. No difference (P>0.05) was found between the score obtained with a automatic embryo freezer(4.0) and a liquid nitrogen container(3.7).