New lithium/calcium complex grease was prepared from oil suspension of lithium hydrate instead of lithium hydroxide monohydrate. The preparation process of the new lithium/calcium complex grease was optimized, and found that the process with oil suspension of lithium hydrate as lithium source shows advantages of short saponification time, less thickener consumption, energy conservative and environmental friendly. As compared with the grease from lithium hydroxide monohydrate, this product has better oxidation stability, more smooth appearance and excellent properties.