Java has been used widely, from servers to cellular phones. In order to test those Java runtime systems, many test tools have been provided. However these tools are not enough for Java JIT compilers. They should be tested by various executable bytecode sequences. Most test tools don't cover such kinds of a combination test. Therefore we developed a random test program generator and a Java JIT compiler test system. This test system automatically 1) generates Java class files which are random, executable and finite; 2) inserts codes that output execution-process-dependent results; 3) runs these on the target JIT compiler and other tested Java runtimes; 4) compares results. In this paper, we describe how to generate random test programs, and how to test a Java JIT compiler, and then we evaluate quality (coverage) of generated random test programs.