In this paper, by using a simple climate model (SCM), a numerical simulation study has been conductedon the scientific and methodological aspects of Brazilian Proposal. First the initial check of simple climatemodel has been done, then we do some sensitivity studies on timeframes (attribution start and end dates,and evaluation date), and three attribution methods (marginal attribution method, proportional attributionmethod, and time-sliced attribution method), at last we get the main conclusions as follows: The simpleclimate model can represent the results of more complex climate model (e.g., HadCM3), and it is thus used tostudy the scientific and methodological aspects of the Brazilian Proposal. Because of the limited knowledgeof science and data, although attributing a part of temperature increase to different GHG (greenhouse gas)emission source, there is considerable temperature increase unattributed to regional emissions. Thereforeit is uncertain to make Brazilian Proposal as the method for the responsibility share of future GHG de-crease emission. The choices of different timeframes (attribution start and end dates, and evaluation date)and future emission SRES (Special Report on Emission Scenarios) make great influence on the regionalcontributions to global climate changes, but different attribution methods have only a little influence. In this paper, by using a simple climate model (SCM), a numerical simulation study has been conducted on the scientific and methodological aspects of Brazilian Proposal. First the initial check of simple climatemodel has been done, then we do some sensitivity studies on timeframes ( attribution start and end dates, and evaluation date), and three attribution methods (marginal attribution method, proportional attribution method, and time-sliced ​​attribution method), at last we get the main conclusions as follows: The simpleclimate model can represent the results of more complex climate model (eg, HadCM3), and it is thus used tostudy the scientific and methodological aspects of the Brazilian Proposal. because of the limited knowledge of science and data, although attributing a part of temperature increase to different GHG (greenhouse gas) emission source , there is considerably temperature increase unattributed to regional emissions. Thereforeit is uncertain to make Brazilian Proposal as the m ethod for the responsibility share of future GHG de-crease emission. The choices of different timeframes (attribution start and end dates, and evaluation date) and future emission SRES (Special Report on Emission Scenarios) make great influence on the regionalcontributions to global climate changes , but different attribution methods have only a little influence.