Many versions of TCP have been proposed for transmitting data, and among them, TCP Reno is most widely used today. However, the problem, that it is difficult to use the wide bandwidth efficiently with TCP Reno, has been pointed out. HSTCP is one of the several new versions of TCP that are proposed to address this problem, but when its flows compete with TCP Reno flows at the same link, HSTCP gains most of the bandwidth and it is impossible to conduct fair transfer. In order to address this problem, we propose a two-level ECN marking to increase the frequency of congestion controls of HSTCP flows, holding its throughput. We evaluate our proposal through computer simulations, and the results show that our proposal mitigates bandwidth allocation to HSTCP, promoting fair transfer with TCP Reno.