New laboratory tests have been developed to characterise thecoke behaviour at high temperature under conditions similar tothose encountered in the blast furnace, especially in terms ofgasification degree. The validity of these new tests has been demonstrated by comparisonwith the modifications undergone by coke in the blast furnace.The latter have been determined by comparing cokes sampledby a tuyere probe with cokes sampled before charging. The results showed only little correlation with the classical coke characterisation indices (I10, I40, CSR), which indicates that they really bring new information on coke properties.