Open kinetic chain exercise has lost favour in rehabilitation after cruciate ligament reconstruction due to concerns that this exercise is harmful to the graft and will be less effective in improving function. Therefore rehabilitation has focused over the past decade on closed kinetic chain exercise. Open kinetic chain and closed kinetic chain exercises were compared for their effects on proprioception, muscle strength and knee instability in the early period of cruciate ligament reconstruction rehabilitation. The study subjects were 14 patients in 28weeks from cruciate reconstruction surgery(11 male, 3 female; mean age = 44.36 years). Closed kinetic chain exercise group used ball, balance pad and air cushion, to perform weightbearing exercises and the open kinetic chain exercise group used elastic rope and N-K table, to perform non-weightbearing exercises. Between tests, subjects trained 5 times per week for 2 weeks. Statistical analysis was by Wilcoxon signed rank test and Mann Whitney U test. In result, this study shows that both open and closed kinetic chain exercise programs lead to an improved muscle strength and Lysholm score. But there was no improvement in proprioception at both exercises. Closed versus open kinetic chain exercise in early period of rehabilitation after cruciate ligament reconstruction surgery do not differ in their effects on knee proprioception, muscle strength and instability. But the effect of closed kinetic chain exercises was showed more improvement than open kinetic chain exercises between pre-post exercises. Therefore further study is required to assess effect of both groups in more long period.