We observed light curve of the exoplanet HD189733b transit at 16/17 of September in 2006. We used photometrical R-filter and each exposure time was 15 s. Photometric analysis is done in AIP4Win2 software and light curve and magnitude error bars in Peranso2.02 sofware. Differential magnitude V-Ens decreasing over 0.03 magnitude was detected. Central time of the transit was 2006 09 16 22:57 (UT). Every data point in the figures is the average of four successive data points and magnitude error bar is standard deviation of these four values. The observing wheather was very good though the half Moon was rising in the eastern sky. The object was setting down in the western sky and so stardard deviation is increasing in the data curve all the time. We used TYC 2141-916-1 (C1), TYC 2141-1508-1 (C2) and TYC 2141-1390-1 (C3) as comparison stars in ensemble photometry. Slight increasing of diffrential magnitude C2-C1 is seen in the second figure. Observers: Veli-Pekka Hentunen and Markku Nissinen.