The radial distribution of feed jet gas concentration in a new type of novel riser in which the jet gas and catalyst contact countercurrent in the injection zone was studied in a large-scale cold mold, and the effects of pre-lift gas velocity and jet gas velocity analyzed. The results show that higher jet gas velocity (Uj=78.5 m/s) and higher pre-lift gas velocity (Ur=4.1 m/s) should be taken in order to obtain a better mixing of feed oil with catalyst particles in the proposed feed injection scheme. Compared with the traditional one, the feed oil can mix with the catalyst particles in a shorter axial distance (H<0.7 m) in the new feed injection structure, which is a great improvement in the promotion of oil mixing. Besides, the distribution of feed jets in the initial contact area of the oil with catalyst is more uniform. Based on the main influential factors of feed jet gas concentration ( , l, q), the empirical formulae for estimating the distributions of jet gas concentration in different zones are established. The calculated results agree well with the experimental data.