This research defines the on-line trading as a sustaining innovation in terms of Clayton M Christensen’s disruptive innovation theory. The researcher chose the representative securities corporations – Polaris, Yuanta Core Pacific, and Fubon Securities as the samples, which have been promoting the on-line trading business. The samples would be divided into groups of heavy, medium and light users according to the sales amount they deal with through on-line trading. And this factor would be taken as a variable. Moreover, The researcher would use MERSI to compare the five crucial management mediate variables – Mind, Ecosystem, resources, strategy and implementation, and take use of the score derived from MERSI corporation check-up list as a general index to differentiate various modes. Meanwhile, the author would adopt the balance scorecard to measure the outcome of the mode’s running results in order to find out the relationship between the model and the results. This research finds out that the key successful elements of heavy, medium, and light users of on-line trading make no difference when comparing to the KSF of the known literature or through the examination of MERSI and the interviews with experts. Furthermore, the management modes of Polaris and Yuanta Core Pacific Securities’ on-line trading are more similar to the successful on-line trading element models set up in this research. This research also finds that on-line trading never cause the creative destruction to the Taiwan securities industry nor completely change the management mode of Taiwan securities. Different levels of on-line trading do lead to the adjustment of the securities traders’ management modes. This research could not find the certain relationship between the mode and the results through the case study though the research gives two connections. This research shows that on-line trading could not replace the traditional trading management mode in a short time. The conditions for people to rely completely on the on-line trading management mode are not so ready. However, the securities corporations with more successful elements of on-line trading will share bigger market share in the future on-line trading market. If the innovative product is neglected, then the traders might suffer from losing the customers because of less on-line trading operation fee. This development would definitely render the relevant business owners the pressure to adjust the management mode, therefore, on-line trading is a crucial variable for the future of the securities corporations. The on-line trading business is a trend for the securities corporations. Since it’s a difficult choice for the securities traders whether they should go for the on-line trading business, this research provides the securities corporations which would like to invest in on-line trading business with some information to refer to.