The present invention pertains to A cyclic process for testing FCC catalysts with resid feedstock on a small scale wherein in a first cycle: a) the feed to be cracked is heated to a temperature between 50 and 500.degree. C., b) the heated feed is injected into a riser reactor containing the FCC catalyst to be tested having a temperature between 500 and 800.degree. C., the injection time being less than 2 seconds, c) an inert gas is injected into the lower end of said reactor riser together in the vicinity of the feed injection in a volume ratio of inert gas to vaporized feed of about 0.03 and 10, the mixing of feed and inert gas occurring in said riser reactor; d) the feed is contacted with the FCC catalyst under fluidized conditions for a contact time of less than 8 seconds; e) the feed is stripped from the FCC catalyst and the properties of the product are analyzed; and in a second cycle a quench liquid is injected into said riser reactor in an amount of up to about 20 wt. % of said feed so as to reduce the temperature in said riser reactor and minimize undesirable secondary reactions. The invention also comprises the apparatus employed to carry out the process. With the process of the invention the mass transfer and diffusion limitations of commercial FCC units are properly simulated.