This paper presented an experimental study about the idle performance of a rotary engine fueled with hydrogen and gasoline blends. The idle speed was reduced from original 2400 to 2300 and 2200 rpm, and hydrogen energy percentage (beta(H2)) was varied from 0% to 35.0%. Test results showed that cyclic variation was raised with the decrease of idle speed whereas reduced with the increase of beta(H2). Both decreasing idle speed and increasing beta(H2) were effective on reducing engine fuel consumption. Total fuel energy flow rate was effectively dropped from 22.4 MJ/h under "2400 rpm and beta(H2) = 0%" to 20.01 MJ/h under "2200 rpm and beta(H2) = 35.0%". Combustion duration was reduced through increasing)3H2. HC and CO emissions were dropped with the increase of beta(H2), but increased after reducing idle speed. CO2 emission was decreased after reducing idle speed and adding hydrogen. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.