Abstract. In the present work, the observed linear polarization data of comet Levy 1990XX are studied at wavelengths 0.485 mum, 0.540 mu m and 0.670 mu m. We propose a model which considers cometary dust as a mixture of compact and aggregate particles, with composition of silicate and organic material. Aggregates correspond to a mixture of Ballistic Cluster-Cluster Aggregate (BCCA) and Ballistic Agglomeration with Migration 2 (BAM2) with a suitable mixing ratio and compact particles correspond to polydisperse spheroids with different axial ratio (E = 0.08 to 1.2) which includes prolate, spherical and oblate particles. It is found from our analysis that the observed polarization data of Comet Levy 1900XX at the above three wavelengths are successfully reproduced by using the proposed model.