There are numerous ways how to test random number generators, we performed only few of them. We let the final judgment on the reader of this chapter, since the author of the tests have no deep knowledge of statistics. However we feel that from these tests all of the generators proved their quality, and it's on the user, which of them will want to use in his/her work. The tests of uniformity showed that Unra generator may have problems with uniform distribution, anyway it seems to be sufficient generator of random number sequences used in computations in Cecile software.