�����ͨ�ӳ�����ˮ���𽥶񻯵����⣬��������ͨ�ӳ����ε�������Ӷ���Ϊ�����ԡ��ر�ˮ����������׼��( GB3838—2002) Ϊ���۱�׼��ѡ��ˮ�ʱ�ʶָ�������������ļ�����ݽ��з������ۺ����ۡ������������ͨ�ӳ�����1999 ��Ϊ����ˮ�壬�������񻯣�2001—2004 �Լ�2008 ��Ϊ�Ӣ���ˮ�壬2005 ��Ϊ���ࡣ����������2003 ����Ϊ���أ�ˮ���а�����BOD5������Ϊ���أ��ֱ�Ϊ19. 41 mg /L ��61. 14 mg /L��

Aiming at the problem of water quality gradual in deterioration in Changchun range of Yitong River�� the authors take“Environmental Quality Standards of Surface Water”( GB3838 �� 2002) as evaluation criteria�� and select water quality identification index method to analyse and evaluate the monitoring of Yangjiawaizi as the representative section data in the last few years�� The results showed that the Changchun range of Yitong River was category V water in quality in 1999��inferior category V water in 2001—2004 and 2008��and category �� water in 2005�� In 2003��ammonia��nitrogen and BOD5 exceed the standard most seriously��which were 19. 41 mg / L and 61. 14 mg / L in content��