The catalytic efficiency of zinc lactate as a catalyst to prepare lactide from lactic acid was evaluated compared ose commonly used catalysts including zinc oxide, solid superacid and stannous octate, which indicated a much catalytic efficiency of zinc lactate than others. After mensurating the chemical structure and the crystal form of zinc lactate and recycled zinc lactate, the effects of catalyst and oligomerization time on the yield of crude lactide and the content of lactic acid in lactide product were studied. As a result, both zinc lactate and recycled zinc lactate showed same chemical structure and were comprised three crystal forms. Using zinc lactate and recycling zinc lactate as a cata- lyst, the yield of lactide were 75.7% ,72.1% , respectively. These indicate that zinc lactate is a kind of cheap, available, recyclable catalyst, which is significant in the industrial production of lactide.