Abstract: Siam weed (Chromolaena odorata) is reputed to be among the world`s most invasive plant species with highly significant economic impact. The distribution, density and growth characteristics (shoot height, leaf area, leaf density, canopy diameter, main stem diameter and mortality) were assessed in a mining ecosystem. The study covered three undisturbed tropical forest sites and three neighboring mine wasteland sites that were 2-15 years post-mining. The growth vigor of C. odorata was compared to that of a dominant native plant species Panicum maximum. The mean leaf density per plant was significantly higher (p<0.0001) among C. odorata in mine lands than in undisturbed forest sites. C. odorata showed significantly (p<0.0001) higher plant density in the mine lands, indicating the conduciveness of disturbed mined lands as habitats that promote invasiveness among the species. Approximately 65% mortality rate of C. odorata occurred under the dense canopy of the undisturbed forest sites and of only 4% mortality rate was recorded for the mined land sites. The native species P. maximum generally depicted lesser growth vigor in the mined lands as compared to the undisturbed forest sites. The mean mortality rate was 55 and 5% within the mined lands and the undisturbed forest sites, respectively. This study identifies the absence of dense canopy and shade as the potential factors promoting the invasiveness of C. odorata and the capacity for spread within the mine land sites.