The present study aims to evaluate the behavior of the flocs and associated structural properties of the aggregates of the flocs concerning varying flocculation intervals at slightly alkaline conditions by coagulation for water treatment. Kaolin was used to prepare synthetic turbid water for which the average hydrodynamic diameter was 1.36 μm and a zeta potential of −12 mV. A jar test was performed to know the optimum coagulant dosage for the turbidity of 250 ± 25 NTU which was found as 250 mg /L, then the test was continued with the optimum dosage for particle size distribution (PSD) analysis and samples were collected at varying flocculation periods of 1, 3, 5, 10, 15 and 20 min. PSD test was conducted using Litesizer 500 and fractal dimension was computed by log–log relation of A ~ lDf. The average hydrodynamic diameter of the flocs after coagulation was found as 39.87 μm and a zeta potential of −10 mV. In the beginning 2 min fractal dimension was increased, then gradually decreased for 15 min and finally attained an equilibrium value of 1.78. There was little difference in the percentage distribution of the size of particles before and after coagulation.