This study aims to develop a real-time QCM (quartz crystal microbalance)-based method for a fungal spore mass measurement system as the indoor air pollutants. Penicillium camemberti (B2), Penicillium caseifulvum (B3), and a mixture of both P. camemberti and P. caseivulfum (B4) were used as the bioaerosol samples in the form of fungal spores. These samples were collected and cultured inside an isolated chamber and mixed with fresh air (filtered by a filter paper) to generate bioaerosol with a diameter of less than 1 μm (fine particles). These bioaerosols were filtered to produce different particle diameters using a particulate cyclone (a filter paper and a suction pump). The developed system consisted of a GO (graphene oxide, a graphene derrivative)-coated QCM (Q1), a bare QCM (Q2), a crystal oscillator, and a frequency counter to process the output signal, QCM’s frequency, and bioaerosol mass. The system shows a good performance with the sensitivity of 27x10^-2 to 29x10^-2 Hz/ng and 23x10^-2 to 29x10^-2 Hz/ng for coated and uncoated sensors, respectively. The best performance is obtained from the coated QCM sensor Q1. The system works well in measuring bioaerosol concentrations with an accuracy of 82% for the coated QCM and 66% for the uncoated QCM. The coated QCM has the potentials of being developed as a fungal spore sensor.