This paper introduces an adaptation of the classical linear control theory representation of zeros, poles and gain into a bilinear approach. The placement of poles at the complex plane is a complete description of plants dynamics; hence it is a convenient form from which calculation of various properties, e.g. rise time, settling time, is plausible. Such technique can be adjusted into the bilinear structure if poles of a quasi-linear representation (linear with respect to input) are concerned. The research outcomes with conclusion on the equivalent poles displacement and generalized rules for a 2nd order bilinear system equivalent poles input dependent loci. The proposed approach seems to be promising, as simplification of design and identification of a bilinear system increases transparency during modelling and control in practical applications and hence it may be followed by applicability of such structure in common industrial problems.