This study has evaluated the possible effect of waste powder of green tea (Camellia sinensis) in feed supplementation on the growth performance, carcass characteristics, blood parameters, and lipid metabolites of growing broilers (chicks) in both the amount and duration aspects of dietary additives during the finisher phases. In the experiment, growth performance, carcass characteristics, blood parameters, and lipid metabolites of broiler chicks have been fully recorded and explored. The diet of 271 day-old Ross 308 male broiler chicks has been supplemented with 0, 0.25, 0.50, 0.75, and 1.00% (w/w) green tea powder in addition to normal feeding additives. The experiment lasted for 21 and 42 days, respectively, for each value of the green tea supplement and for separate groups of animals. Broiler feed has been supplemented with different levels of green tea powder to assess the trial effect and potential beneficial dose on selected growth performance, carcass characteristics, and blood parameters of broiler chicks. Although there are almost no differences of broiler parameters and characteristics measured from one point of view of single treatment factor (amount or duration), against the control groups during the three trial periods, the overall effect of amount and duration of feeding green tea powder is positive on growth performance, carcass characteristics, blood parameters, and lipid metabolites of growing broilers, although there are nearly no differences in some broiler parameters and characteristics. However, there are a remarkable interactive effect of amount and duration of different feeding levels of green tea powder and obvious differences observed in all the parameters and characteristics of growing broilers. Especially, usage of feeding green tea powder largely decreased the abdominal fat content and some lipid metabolites, including VLDL cholesterol, LDL cholesterol, triglycerides, and AST of broiler chicks. While additional data are still needed to evaluate and analyze the optimum supplement feed doses, it can be concluded that dietary green tea is a positive feed supplementation to reduce abdominal fat and lipid metabolites and induce antioxidants.