Infants behaviors to the eight novel objects were recorded by V. T. R. They were analyzed with vision, contents of manipulation (vigorous manipulation with arms and hands(vertical shake, horizontal shake, hit drop), gentle manipulation with fingers (finger, pinch, scratch), oral behaviors (mouth, appropriate manipulation)) and other behaviors . The Ss were 66, 7-, 9-, 12-month old infants. Simple objects, viz.(1) Ring,(2) Bar,(3) Spoon,(4) Cup were manipulated with arms and mouthed more than complex objects, viz.(5) Figure Box,(6) Rainbow Spring,(7) Uneven Basket,(8) Decorative Rattle. Complex objects were visually regarded and manipulated with fingers more than simple objects in all age groups. Among complex objects, visually complex objects,(5),(6) were visually regarded and manipulated with arms more than tactually complex objects (7),(8). The latter were manipulated with fingers and received emotional responses (vocalization, look at the mother, being afraid) more than the former. The 9-and 12-month old infants had longer visual regard per response, larger percentage of looking within one trial, and longer manipulative latencies than 7-month old infants. And the total manipulation time decreased with age. The manipulations with arms decreased and the manipulations with fingers increased with the age. The latter had larger percentage of responses of visual regard than the former. Males had longer visual regard per response, total manipulation and vigorous manipulation with arms than females. Oral behaviors decreased with the age. But regarding objects (3) and (4), mouthing of their special round parts increased with the age, and 12-month old infants began to manipulate them appropriately. Looking at the mother increased with the age, and 12-month old infants began to point or show the stimulus to the mother.