Abstract.In this note all rings considered are associative with an identity element 1 and all modules are unital left modules. It is shown that a commutative ring R has principal ideals projective if and only if i? [X] has the same property. Furthermore it is proved that a ring R has all «-generated left ideals flat if and only if all »-generated right ideals are flat. In the last part of this note we will prove the following results: Fix »2:1. Then there exists a ring R such that all »-generated left ideals are projective, in particular, flat, while there exists a nonflat (» + l)-generated left ideal.