en عمومى General پژوهشي Research paper As a counterpart to best approximation, a new kind of approximation, called best coapproximation was introduced in normed linear spaces by C. Franchetti and M. Furi. In this paper, we use this coapproximation to prove some results on the existence and uniqueness of best coapproximation in quotient spaces when the underlying spaces are metric linear spaces. We shall also see how coproximinality can be transmitted to and from quotient spaces. Best coapproximation, co-Proximinal set, co-Chebyshev set, Boundedly compact set, Pseudo co-Chebyshev set. 13 20 http://ijmsi.ir/browse.php?a_code=A-10-1072-1&slc_lang=en&sid=1 S. Gupta sahilmath@yahoo.in 10031947532846007028 10031947532846007028 Yes Guru Nanak Dev University T. Narang tdnarang1948@yahoo.co.in 10031947532846007029 10031947532846007029 No Guru Nanak Dev University