Since stock equity of joint stock company is the principal subject matter in curb market transactions，most of listed enterprises in the over-the-counter market are limited liability companies. This market is set up for micro，small and medium enterprises，but joint stock company is the most common organizational form in micro，small and medium enterprises. According to the relevant regulations，if a limited liability company wants to convert its audited net assets into shares to be a joint stock company，its business performance can be calculated continuously. To convert a limited liability company into a joint stock company is an inevitable path to enter the over-the-counter market. Regulating the tax issue related to converting net assets to shares can better promote the healthy development of enterprises in the over-the-counter market.