The mean square end-to end distances〈h2(c)〉of confined radom walks (R W) and confined self-avoiding walks (S A W) have been obtained by means of Monce Carlo simulation on a simple cubic lattice. The geometry of confinement considered includes: a cubic box'or a sphere. an infinice tube of square ofr circular cross section, and a gap between two parallel infinite plates, corresponding to confincements in three, two and one dimertsions respectively. The〈h-(c)〉value of a confined R W chain decreased monotonically with decreasing confinement size and approached to a value of 0, 1/3 and 3/2 of 〈h2(o)〉is the mean square end-to-end distance of a R W chain without any confinenent. A S A W chain confined in a cubic box also showed a continuous decreise of 〈h2(O)〉with decreasing coafiement size. However. a S A W chain confined in two and one dimcasionsshowed a minimum value of 〈h2(c)〉/〈h2(O)〉with deerteasing confinement size.