We describe properties of the nonstandard q-deformation $U'_q({ \rm so}_n)$ of the universal enveloping algebra $U({ \rm so}_n)$ of the Lie algebra ${ \rm so}_n$ which does not coincide with the Drinfeld--Jimbo quantum algebra $U_q({ \rm so}_n)$. Irreducible representations of this algebras for q a root of unity q^p=1 are given. These representations act on p^N-dimensional linear space (where N is a number of positive roots of the Lie algebra ${ \rm so}_n$) and are given by $r={ \rm dim} { \rm so}_n$ complex parameters.
Categories: math.QA math.RT