Abstract Chaenomeles sinensis (Thouin) Koehne fruits were traditionally used for food and medicinal materials. With the aim of providing necessary reference about the micro-powder as ingredients in food and medicine, this study investigated the physicochemical properties and antioxidation of three C. sinensis (Thouin) Koehne fruit micro-powders, prepared by pulverizing its coarse fruit powder with planetary ball mill for different periods of time. The results demonstrated that planetary ball mill could effectively pulverize coarse powder to different micro-sizes. As milling time increased, the median diameter was significantly decreased and particle size distribution width narrowed, the angle of repose and swelling capacity improved to a different extent, oil holding capacity of micro-powder was not affected, the water holding capacity, total flavonoid content, DPPH and NO2− radical-scavenging capacity and reducing power were decreased. The results suggested that micronize processing could improve some properties of C. sinensis (Thouin) Koehne fruit powder. Industrial relevance The plant Chaenomeles sinensis (Thouin) Koehne is known locally as “Guang Pi Mu Gua”, one of the Chinese traditional food and drug fruits, has a golden color and with full-bodied fragrance, and is enriched in dietary fibre, organic acid and some biologically active pentacyclic triterpene acids such as oleanolic acid and ursolic acid. Moreover, its yield was very large, e.g. the total yield has over 100,000 tons in 2006 just in Baihe County, Shaanxi, China. So it is very significant to study its processing. Recently, there has also been a rapid development in micron technology applications along with nanotechnology to develop products that explore novel properties in food and drug industries. Physical and functional properties of some Chinese traditional medicines were found to change with particle size during superfine grinding. So, we begin this research.