Abstract: In view of the power of the northern states of Liao and Jin,the embassies sent between Song and Gaoli were subjected to economic and cultural development than to changes of political climate.In the circumstances,the embassies always combined trade to their diplomatic mission,which could be called governmental-attached trade consisting of three forms.One was Sidi,the means of exchange of the presents between the envoys and the sovereign or the officials who received them.And the other two were th..