A 3-day experiment was conducted to evaluate the emission of particulate matters (PM(s)) by firewood cook stove in a rural home. No large industrial combustion in a 2-km radius and a provincial road is ~500-m away with dense trees in between. One Plantower PMS7003 was used to measure PM2.5 and PM10. The ratios of PM(s) while cooking was compared with the average of PM(s) the immediate background (IBC) and average concentration (ABC). The IBC is the average PM(s) concentration of two-hour before and two-hour after the cooking and the ABC is the PM(s) concentration on that day excluding the time of cooking. This study found that the PM(s) emitted by the firewood stove was from 6 to 125% more compared to IBC and 65 to 95% more than ABC. In addition, the background concentration of PM(s) was more dynamic and changed wildly during the 3-day run. The background of PM2.5 concentration was from 38 to 58µg/m3 averaged daily.