Poland will provide around 320 tonnes of relief supplies, including food, blankets and mattresses, Xinhua reported.
The first convoy, containing around four to five loaded trucks had already left on Monday.
Once the convoy reaches Lvov, it will be unloaded, while the further distribution will be done by the Ukrainian side.
The Polish humanitarian aid for the Ukrainian soldiers is a result of an agreement between the two countries, which was reached Aug 14.
Fundraising is being organised in Poland to provide food, clothing and other daily necessities for Ukrainians displaced from eastern Ukraine.