There is disclosed novel eburnamonine oxime, its derivatives and salts, process for the manufacture thereof and pharmaceutical agents containing the same. The compounds are represented by the following formula. ##STR1## wherein R is hydrogen, alkyl, alkoxyalkyl, or oxisilanylalkyl group or a group of ##STR2## R.sup.1 and R.sup.2 are same or different and respectively hydrogen, alkyl having 1 to 4 carbon atoms, aryl or aralkyl group, or R.sup.1 represents together with R.sup.2 and the neighboring nitrogen atom a non-substituted or substituted heterocyclic ring, and n is an integer of 2 or 3.