Abstract: Through the well unclosing-in test analysis method introduced in this paper,the same formation parameters as the build-up or drawdown test are obtained by two-stage flowrate curve,which is tested by way of the change of working system under the well unclosing-in.Therefore,this method is a field testing technology with broad developing prospects.The method has been tested and studied since 1989.The computer program is developed,which is easy to realize analysis,calculation,print and plotting,and the satisfied results are received in the technology and parameter interpretation through the field practice and analysis research of 4 years.