Gardens and urban forests provide various benefits, including recreation, healing, disaster prevention, particulate matter reduction, promotion of biodiversity, and temperature reduction. Recently, there has been growing interest in the carbon sequestration effect, wherein plants uptake and store carbon dioxide from the air through their growth. To quantify the carbon sequestration effect of gardens and urban forests and calculate the uptake amount, various carbon sequestration factors for each species, such as wood density, biomass expansion factor, root content ratio, and carbon content factor, are essential. Therefore, this study developed a carbon sequestration factor for each species in order to identify and quantify the carbon sequestration effect of 5 shrubs planted in gardens and urban forests. The materials are 250 plants produced in Chung-cheong area, and carbon sequestration factor was measured by classifying the plants that were directly harvested by parts(leaf+twig, branch, stem, root). As a result of the study, wood density was calculated in the order of C. dichotoma(0.67g/㎤), L. obtusifolium(0.63g/㎤), N. domestica(0.55g/㎤), C. alba(0.45g/㎤), and W. subsessilis(0.44g/㎤). Biomass expansion factor was calculated in the order of W. subsessilis(4.57), C. alba(4.25), C. dichotoma(3.76), N. domestica(3.07), and L. obtusifolium(2.29). The root content ratio was calculated in the order of N. domestica(0.64), C. dichotoma(0.40), W. subsessilis(0.30), C. alba(0.29), and L. obtusifolium(0.27). The carbon content factor was calculated in the order of W. subsessilis(45.91%), N. domestica(45.67%), C. dichotoma(45.32%), L. obtusifolium(45.04%) and C. alba(44.99%). In addition, appropriate variables were selected using a Machine Learning process in MATLAB, and relative allometric equations were developed to estimate carbon storage through SPSS Statistics regression analysis. The study results will contribute to accurately estimating the carbon sequestration effect of gardens and urban forests.