This article uses discriminant sampling method to select 1062 small and micro enterprises from 25 provinces in China. Researches were conducted on their credit demand and credit behavior, with the Probit model to carry out metrologic tests on influential factors of these enterprises’ credit demand and credit behavior.The metrologic analysis shows: Literacy level of leader, asset size, annual revenue of the enterprises have significantly positive effects on the credit demand of these small and micro enterprises. Annual revenue has significantly negative influence on overall credit behavior and the occurrence of informal financial behavior, but significantly positive influence on the occurrence of formal financial behavior. Literacy level of staff and asset size of enterprises have significantly positive influence on the occurrence of the overall credit behavior of small and micro enterprises. This article uses discriminant sampling method to select 1062 small and micro enterprises from 25 provinces in China. Researches were conducted on their credit demand and credit behavior, with the Probit model to carry out metrologic tests on influential factors of these enterprises’ credit demand and credit behavior.The metrologic analysis shows: Literacy level of leader, asset size, annual revenue of the enterprises have significantly positive effects on the credit demand of these small and micro enterprises. Annual revenue has significantly negative influence on overall credit behavior and the occurrence of informal Financial behavior, but significantly positive influence on the occurrence of formal financial behavior. Literacy level of staff and asset size of enterprises have significantly positive influence on the occurrence of the overall credit behavior of small and micro enterprises.