Abstract: Abstract: Peat and vermiculite are usually used as cultivation substrates to produce potato mini tubers but the peat is non-renewable resource. There is no enough peat that can be used as cultivation substrate to produce potato mini tubers. The vermiculite is used as substrate material for one year usually. When we use vermiculite as cultivation substrate to produce potato, we may spend more money because the repetition utilization rate of the vermiculite is low and the vermiculite is expensive. Corn stalk resource is rich and its price is low, however, corn stalk as cultivation substrate has not been used efficiently in potato mini tubers cultivation. In order to make full use of the corn stalk, we carried out the experiments. This experiment studied the application effect of corn stalk substrate in the production of potato mini tubers. Through the comparative analysis of the test results, we hope we can find out more suitable application ratio of cultivation substrate for producing potato mini tubers. This paper took the potato Chunshu No.4 virus-free seedling and 5 different substrates including corn stalk, peat, vermiculite, sand and soil as experimental materials. We used the corn stalk through fermentation treatment. We sieved the peat by 1 cm aperture. These 5 kinds of substrates were mixed in various ratios to form 6 compound substrates: M1 (peat : vermiculite=1:1), M2 (corn stalk : peat : vermiculite=1:1:2), M3 (corn stalk : peat : sand=1:3:4), M4 (corn stalk : peat : sand=1:1:2), M5 (corn stalk : sand : soil:3:4:1) and M6 (corn stalk : soil=3:2). We used the 500 times liquid of 50% wettable powder of Duolaibao pesticide and the 1000 times liquid of 50% wettable powder of Duojunling fungicide for insecticidal sterilization after the substrate materials were mixed evenly in various ratios. Before the experiment, we made the land leveling in the greenhouse and put insect-proof screen on the land. We used the bricks to make 9 test flumes. The length of the test flume was 2.4 m and the width was 1 m. The passage was 40 cm between the test flumes. We divided the test flume into 2 experiment plots with equal area. There were 18 experiment plots. The area of each experiment plot was 1.2 m2. Random block method was used in the experiment and the tests were repeated three times. Before the potato virus-free seedlings were planted, we put the sunshade net with the transmittance of 50% above the greenhouse. We took down the sunshade net after the rejuvenation period of the potato virus-free seedlings. Starting from the time that the potato virus-free seedlings were planted in the greenhouse, random sampling was carried out every half a month. The effects of 6 kinds of substrates with different ratios on the form and physiology of the potato virus-free seedlings were analyzed and compared. The form indicators of the potato virus-free seedlings included plant height, stalk width, leaf number, stem number, above-ground mass and root mass, and the physiology indicators of the potato virus-free seedlings included chlorophyll a, chlorophyll b, total chlorophyll and root activity. The results indicate that M2 (corn stalk : peat : vermiculite=1:1:2) is better than the other experiment substrates, on plant height, stalk width, above-ground fresh mass, chlorophyll a and total chlorophyll, and provides more nutrients for potato mini tubers during the period of growth.