im australian looking to marry in chongqing

im australian i am planning to marry my fiance in chongqing yes she is a local resident of chongqing what papers and documents do i need to marry and what is the process i have a single status certificate i have divorce papers from a previous marriage and a valid passport do i need anything else i have been told i have to get a certificate of no impedment issued in china or a hand written letter saying i am free to marry issuede in china can anyone help