Abstract: In order to ascertain influence of cold plasma treatment on germination of tomato seeds, tomato seeds of Zhezhen1（2018）, Zheza205（2019）, Zhefen716（2023）and Zhefen202（2019）were treated for 15 seconds by a cold plasma seed processing apparatus with power of 40, 50, 60, 70, 80 and 90 W, when environmental medium was set to be air and absolute pressure was set to be 150 Pa in vacuum chamber of apparatus．Then the seeds were placed for 7 days and used for germination test．Results showed that, when processing power was smaller than 40 W, influence of cold plasma treatment on germination of tomato seeds was slightly．A better processing power for tomato seeds of Zhezhen1（2018）, Zheza205（2019）, Zhefen716（2023）and Zhefen202（2019）was 50 W, germination vigor of seeds after treatment increases by 4.00%, 6.75%, 11.25% and 5.00% respectively, while germination rates increase by 2.50%, 3.00%, 6.75% and 4.75%．With increase of processing power, facilitation of cold plasma treatment on germination of tomato seeds tends to reduce, processing power should not be lager than 80 W．