The in situ measurement of Comet 1P/ Halley and the ‘ Stardust ’ returned samples of comet Wild 2 showed the presence of a mixture of compact and aggregate particles , with composition of both silicates and organic refractory in cometary dust . Recently , the result obtained from ‘ Stardust ’ mission suggests that the overall ratio of compact to aggregate particles is 65:35 ( or 13:7 ) for Comet 81P/Wild 2 ( Burchell et al . 2008 , Meteoritics & Planetary Science , 43 , 23 ) . In the present work , we propose a model which considers cometary dust as a mixture of compact and aggregate particles , with composition of silicate and organic . We consider compact particles as spheroidal particles and aggregates as ballistic cluster-cluster aggregate ( BCCA ) and ballistic agglomeration with two migrations ( BAM2 ) aggregate with some size distribution . The mixing ratio of compact to aggregate particles is taken to be 13:7 . For modeling Comet 1P/ Halley , the power-law size distribution n ( a ) \sim a ^ { -2.6 } , obtained from re-analysis of the Giotto spacecraft data , for both compact and aggregate particles is taken . We take a mixture of BAM2 and BCCA aggregates with a lower cutoff size around 0.20 \mu m and an upper cutoff of about 1 \mu m . We also take a mixture of prolate , spherical and oblate compact particles with axial ratio ( E ) from 0.8 to 1.2 where a lower cutoff size around 0.1 \mu m and an upper cutoff of about 10 \mu m are taken . Using T-matrix code for polydisperse spheroids ( 0.1 \mu m \leq a \leq 10 \mu m ) and Superposition T-matrix code for aggregates ( 0.2 \mu m \leq a _ { v } \leq 1 \mu m ) , the average simulated polarization curves are generated which can best fit the observed polarization data at the four wavelengths \lambda = 0.365 \mu m , 0.485 \mu m , 0.670 \mu m and 0.684 \mu m . The suitable mixing percentage of aggregates emerging out from the present modeling corresponds to 50 % BAM2 and 50 % BCCA particles and silicate to organic mixing percentage corresponds to 78 % silicate and 22 % organic in terms of volume . The present model successfully reproduces the observed polarization data , especially the negative branch , for comet 1P/Halley at the above four wavelengths , more effectively as compared to other work done in the past . It is found that among the aggregates , the BAM2 aggregate plays a major role , in deciding the cross-over angle and depth of negative polarization branch .