During financial crisis, non-financial firms may face with credit tightening, lack of liquidity or go bankrupt because of unaffordable ability in accessing capital and funds. This paper focuses on investigating the severity of financial constraints across firms during that hard time and go further examining whether there is any substantial impact of financial constraint on firm’s stock performances and firm operational performance. We highly believe that financial statuses may decide the performance of firms, which is referred to stock returns and efficiency, respectively, over time. Our empirical results show that financial constraints generate significant effects on firm stock returns. Specifically, these impacts become severely and spread widely across non-financial firms during 2008-2009 global crisis. Our results further imply that financial constraints may mitigate the efficiency of firm operational performance over time because of constrained inputs.