\input zb-basic \input zb-ioport \iteman{io-port 00957054} \itemau{Yablonskaya, K.A.} \itemti{Constructing a basis for third degree impedance functions.} \itemso{Mosc. Univ. Comput. Math. Cybern. 1994, No.3, 58-52 (1994); translation from Vestn. Mosk. Univ., Ser. XV 1994, No.3, 60-64 (1994).} \itemab Functioning of passive two-pole circuits is described by a complex rational function which is called an impedance function. Then the problem of synthesis of such functions is discussed for the case of rational functions of degree $(3,3)$. All the nineteen types of denominators are denoted by $S_{i}$, $i=1,\ldots,19$. The notion of basis for the intersection of $S_{i}$ is introduced. The bases for $S_{1},\ldots,S_{6}$ and $S_{9},\ldots,S_{14}$ are obtained. \itemrv{P.Y.Yalamov (Russe)} \itemcc{} \itemut{rational function; synthesis of impedance functions} \itemli{} \end