Common Problem in e-commerce operation is about customer's trust. There are many effort have been done to gain customer's trust. One of these effort is to improving website USAbility. Improvement of website USAbility will be enhancing effectivity, efficiency and user satisfaction. With always keep and improve effecivity, efficiency and user satisfaction of website's USAbility will improve customer's trust. This research proof hypotesis that customer's trust (dependent variabel) in e-commerce model B2C influenced by website's USAbility factor. There are four USAbility factor defined (independent variabels) : graphic design, structur design, content design and social cue design. This qualitative research using user survey method for gathering data, and using Regression –Correlation test to know the relationship between variabels. Result of this research show that graphic design, structur design, content design and social cue design positive influencing customer's trust. Content design have highest correlation rather then three other of website's USAbility factor. Level contribution of all USAbility factor defined to customer's trust is 43,2%. It's means there are other aspects that also influencing customer's trust beyond that four USAbility factor that need to deeper analysis.