A freeze-preserving agent includes trehalose, HEPES and human albumin protein, and the freeze-preserving agent includes no KCl, NaCl, EGTA and EDTA. This freeze-preserving agent is for freeze preservation of mitochondria.一種冷凍保存劑,包含海藻糖、HEPES以及人類血清白蛋白,且此冷凍保存劑不包含氯化鉀、氯化鈉、乙二醇四乙酸以及乙二胺四乙酸。前述冷凍保存劑可用於粒線體的冷凍保存。