Abstract: Background and Objective: Tea (Camellia sinensis (L.) O. Kuntze) is the economically important beverage intensively managed as a plantation crop. The study aims to quantify the biomass allocation patterns of young tea plants and how this is influenced by the growth environment, age, genotypes (BSS-1 and UPASI-9) and soil types (Oxisols and Ultisols). Materials and Methods: The fractions of tea plant mass represented by foliage, twigs, stem, woody and feeder (fine) roots were measured with uprooted tea plants by wet excavation method between 2010 and 2015. Age-response curves of allocation were constructed by statistical analysis from panoply of multisource experimental data and the difference between age, genotype and soil was tested by one-way (ANOVA) with a Tukey’s post hoc test. Results: The results revealed that the biomass of the tea plant and the relationship between fine roots and shoots (R/S), fine roots to foliage biomass (FR/L) and aboveground to belowground biomass (AGB/BGB) ratio were significantly (p>0.01) altered as a function of age in response to soils and genotypes. The greatest percentage of total biomass was allocated within the AGB (54-58%) than BGB (46-42%) in tea plants showing that AGB sinks larger portion of carbon. Classification and regression tree (CART) and structural equation modelling (SEM) analyses showed the complex change in biomass and allocation was affected by the meteorological factors (temperature and rainfall), soil attributes (pH, EC and K) and microbial population (bacteria and fungi). Conclusion: This study concluded that the allocation of the biomass of tea plants is supported by the optimal partitioning theory, where environmental factors impose integrative effects on the plant to allocate biomass to the organ that acquires the most limiting resource to maximise their growth rate.