Yukwa samples, made with additions of 0, 10, 20, and 30% Rubus coreanus Miquel extract, were puffed by different puffing methods(convection oven, microwave oven, and fryer) and were then examined for quality characteristics such as moisture content, expansion rate, color, hardness, and sensory qualities, in order to determine the optimal ratio of Rubus coreanus Miquel extract in the formulation and the optimal expansion of Yukwa. The moisture contents of Yukwa base increased as the level of Rubus coreanus Miquel extract increased. And the Yukwa puffed by convection had higher moisture than the samples puffed by microwave oven or frying, with the exception of the sample containing 20% Rubus coreanus Miquel extract. When comparing the expansion rates of samples, no significant differences were found between the control and extract-containing samples puffed by convection, microwave, and frying methods, respectively. However, the sample puffed by frying had the highest expansion rate, whereas the convection-, microwave-puffed samples showed no significant differences. In the convection-, microwave-, and fryer-puffed samples, lightness and yellowness decreased, but redness increased, as the level of Rubus coreanus Miquel extract increased. And the sample puffed by microwave oven had greater lightness as compared to the samples puffed by convection and frying. In terms of hardness, no significant differences were found the control and extract-containing samples puffed by convection and microwave methods. However, hardness was maximal in the sample puffed by convection and lowest in the sample puffed by frying, in which it increased according to the addition of Rubus coreanus Miquel extract. In the consumer acceptance evaluations and characteristics intensity rating tests, the samples puffed using convection and microwave methods showed higher scores for the majority of evaluated characteristics as compared to the samples puffed by frying. And the samples containing Rubus coreanus Miquel extract obtained fairly good scores. In conclusion, the results indicate that additions of 10$sim$20% Rubus coreanus Miquel extract are optimal for Yukwa that is puffed by convection and microwave methods, as this range provides good physiological properties and reasonably high overall consumer acceptability.