This paper presents the results of the study taken in ThaDua Wastewater Treatment Plant of Vientiane city to investigate the Use of municipal sludge with soil on Marigold flower growth in pot experiments. Sludge samples from the rice farm were examined periodically during the period from February to June 2010 using the chemical analytical method for soil, Organic matter (OM) was measured with volumetric analysis using Walkley and black method. The pH value was measured in a 1:1 (w/v), using pH meter. The plant was grown for 75 days, approximately 2.5 months (between April and June 2010). The bacteriological and chemical characteristics of the sludge after centrifuging were measured in order to establish the possibility of land disposal. And the Results for Marigold flowers as the chosen for the experiment, were that all mixtures of castings (C) with PP, PBS, except 3 PP: 1 C (v/v), increased the growth index of plants.