Abstract: Cyanogenic glucosides were reduced or eliminated in order to obtain safe and non-toxic cassava varieties. In this study, the expression of a cyanogenic glucosidase gene was investigated in five cassava varieties (high-cyanide and low-cyanide) by RT-PCR. Linamarase was synthesized in the aboveground tissues of the plant and no expression was found in the underground part; the expression level of terminal bud on the aboveground part was much greater than the expression level of stems and mature leaves; no expression appeared in tuberous root of low cyanide and high cyanide varieties. No significant difference in expression was found on the terminal bud of high cyanide and low-cyanide cassava; however, higher expression appeared in leaves and stems of low cyanide cassava. The expression of linamarase in different varieties and different tissues of cassava was different. The study could provide certain reference for safe and non-poisonous cassava variety screening.