Streamflow drought index (SDI) with 6-month was calculated using monthly runoffs as hydrologic drought analysis indicator at three hydrologic stations of Shuikou

Sikou and Chaoan during 1956-2011. And extraction of two variable element which is duration and degree of drought through run theory as well as analysis the drought characteristics of Hanjiang based on two variable joint probability distribution's method. The distribution of P-III was selected as the drought duration marginal distribution and the distribution of Weibull was selected as the drought degree marginal distribution by comparing each distribution fitting index. In order to obtain the design value of \ joint return period and co-occurrence with duration and degree of drought using joint distribution structured by GH Copula. For the sake of obtain conditional probability of drought duration or drought degree under the each one

to consider combination of different duration and degree of drought. Seen from the results

the greater risk of facing drought by Meijiang is more than the Hanjiang downstream.