We present a thorough experimental and theoretical study of micrometer-sized particle dynamics in optical
lattices. The spatial parameters of the lattices are set by configuration of the interfering beams with computercontrolled
spatial light modulator. The behaviour of particle confined in the interference pattern is monitored
by fast CCD camera. Analyses of the particle trajectory and Brownian motion reveal force interaction between
the particle and the lattice. We use polymer microspheres as the experimental objects. The experimental results
are compared with the theoretical predictions based on the generalized Mie theory.