Metal nano-particle has great potential to change optical, thermal and electric properties. One promising application in recent years is the application for the printable electronics as metal nano-ink. To ensure the reliability of the printable electronics, improvement of the adhesion strength between metal nano-ink and substrate is important. In this study, thin Au coat was introduced to the substrate surface, and its effect on the spreading of silver nano-ink was experimentally investigated. In the experiment, the contact angle variation of the silver nano-ink was measured at the different surface treatment conditions to glass plate and polyimide film. The stain size of a single droplet was also measured at different surface conditions. The results showed that the contact angle of the ink was complexly changed with the Au coat thickness. Therefore, precise design of surface treatment is important to correctly control the spreading process for metal nano-ink.