Harmonic distortion is one of the disorders in the building's electrical system. The harmonic distortion that comes from a non-linear load that could bring a wave of frequency multiples of the fundamental frequency. The study Analyses Current and Voltage Harmonics at Building B of Universitas ‘Aisyiyah Yogyakarta aims to find out the value of harmonic distortion in the electrical system with the reference of the IEEE 519-1992. Parameter measurement of voltage, current, Total Harmonic Distortion Voltage (THDV), Total Harmonic Current Distortion (THDI), and Total Demand Distortion Current (TDDI). The measurement of the use of Power Quality and Energy Analize METREL MI 2892. Studies located in panel Sub Distribution Panel (SDP) Building B of Universitas 'Aisyiyah Yogyakarta. Time measurement for a week with the time setting on the appliance for 24 hours and time-lapse recording for 30 minutes. The results of the measurements show the highest harmonic value of 50.38% and the harmonic voltage of 5.35% in Building B University isy Aisyiyah Yogyakarta exceeds the IEEE standard limit 519-1992 for maximum voltage harmonics of 5% and maximum harmonics of 8%. Harmonics that exceed the standard must be reduced by using a single tuned passive filter. The result of the value of the single-tuned passive filter specification for 3rd order is Xn = 1297.8 Ω; XL = 1297.8 Ω; XC = 1297.8 Ω; R = 43.26 Ω; P = 3,338 KW; L = 1.425 H; C = 0.846 μF and for 5th order is Xn = 731.7 Ω; XL = 731.7 Ω; XC = 731.7 Ω; R = 24.39 Ω; P = 5.92 KW; L = 47,556 H; C = 0.883 μF.